Affinity guided isolation, structure elucidation and total synthesis of laetirobin a and its analogue synthesis for therapeutic development 1 4

The aqueous layer was extracted 4 times and the combined organic layers were washed four times with water, dried over Na2SO4 and evaporated under vacuum.. The combined organic layers wer

Appendix 1

Experimental Section

Appendix 1

Experimental Section

Experimental Section

General Remarks

Chemicals and working techniques

Unless otherwise stated, all reagents were obtained from Acros, Aldrich, Alfa Aesar, Fluka, Merck or TCI America and used without further purification Commercial anhydrous solvents were used throughout and transferred under an argon atmosphere Additionally, DCM was dried by distillation over CaH2, and THF was dried by distillation over sodium benzophenone ketyl Absolute triethylamine and diisoproylamine were distilled over CaH2 prior to use All reactions were performed under argon atmosphere and stirred magnetically in oven-dried glassware fitted with rubber septa Inorganic salts and acids were used in aqueous solution and are reported in % w/v

NMR spectroscopy

All spectra were measured on a Bruker Avance ACF 300 or Bruker Avance AMX 500 spectrometer The Bruker Advance 300 spectrometer operated at 300 MHz for the 1H and 75 MHz for 13C nuclei, respectively The Bruker Advance 500 spectrometer operated at 500 MHz for the 1H and 125 MHz for 13C nuclei, respectively Spectra were recorded at 295 K in CDCl3 unless noted otherwise Chemical shifts are calibrated to the residual proton and carbon resonances of the solvents: CDCl3 (δH = 7.26 ppm, δC = 77.0 ppm) Data are reported

as follow: chemical shift (multiplicity: s = singlet, d = doublet, t = triplet, dd = doublet of

doublet, m = multiplet, b = broadened, J = coupling constant (Hz), integration)

Mass spectrometry

Low resolution mass spectral analyses were recorded on Finnigan LCQ (ESI ionisation source) High resolution mass spectral analyses were recorded on Finnigan MAT95XL The used mass spectrometric ionisation sources were electron impact (EI) and electrospray ionisation (ESI) High resolution mass (HRMS) analyses were referenced against perfluorokerosene Some of the mass spectra were measured on a Shimadzu ESI-TOF Low resolution mass is reported as follow: ionisation sourceionisation mode: found mass (percent of adduct) High resolution mass (HRMS) is reported as follow: (ionisation source) found mass [calcd [related species] of calculated mass for formula of related species]

Infrared spectroscopy

FT-IR spectra were recorded on a Fourier Transform infrared spectrometer model IR

Prestige-21 (Shimadzu) Solid or crystalline samples were pulverized with potassium bromide (KBr) and percent transmittance (T%) was measured The percent transmittance (T%) of liquid samples or oils were measured in film between sodium chloride (NaCl) discs Absorption band frequencies are reported in cm-1

Chromatographic methods

Analytical thin layer chromatography (TLC) was performed on pre-coated with silica gel 60

F254 glass plates (Merck) The compounds were visualised by UV254 light Non-UV active compounds were visualized by staining the developed glass plates with an aqueous solution of molybdophosphorous acid or an aqueous solution of potassium permanganate (heating with a

hot gun) Staining solutions were prepared as follow: Ceric ammonium molybdate: 24 g

ammonium molybdate [(NH4)6Mo7O24•4H2O] and 0.5 g Ce(NH4)2(NO3)6 were dissolved in

400 mL of aqueous 10% H2SO4 Potassium permanganate: 2.5 g KMnO4 and 12.5 g

Na2CO3 in 250 mL H2O

Flash chromatography and dry column vacuum chromatography (DCVC) were performed using EMD or Silicycle® silica gel 40–63 µm particle size, 40 or 60 Å pore size and 25–40

µm particle size, 60 Å pore size, respectively

Analytical HPLC-MS was performed using Shimadzu Prominence series connected with ESI/TOF; column: XTerraTM MS C18, 2.5µm, 2.1·30mm; gradient: 0-0.5 min, 10% B; 0.5-3.5 min, 100% B; 3.5-9.0 min, 100% B; 9.0-9.5 min, 10% B; 9.5-15.0 min, 10% B; flow: 0.4 mL•min-1

Preparative HPLC was performed using a Gilson machine (liquid handler GX-271, UV detector UV/VIS 151 and pump model 321); column: XTerraTM prep MS C18 OBDTM, 5µm, 19·50mm; gradient: optimized for each sample; flow: 10.0 mL•min-1

X-ray crystallography

Crystals were mounted on glass fibres X-ray data were collected with a Bruker AXS SMART APEX diffractometer, using Mo-Kα radiation at 223K or at 100K, with the SMART suite of programs (SMART, version 5.628, 2001 Bruker AXS Inc., Madison, Wisconsin, USA) Data were processed and corrected for Lorentz and polarization effects with SAINT (SAINT+, version 6.22a, 2001 Bruker AXS Inc., Madison, Wisconsin, USA), and for absorption effect with SADABS (SADABS, version 2.10, 2001 G W Sheldrick, University of Goettingen, Germany) Structural solution and refinement were carried out with the SHELXTL, suite of programs (SHELXTL, version 6.14, 2000 Bruker AXS Inc., Madison, Wisconsin, USA) All structures were solved by direct methods to locate the heavy atoms, followed by difference maps for the light, non-hydrogen atoms All non-hydrogen atoms were generally given anisotropic displacement parameters in the final mode All H-atoms were put at calculated positions

Note: Copies of the coordinates for selected structures have been uploaded to the Cambridge

Crystallographic Data Centre (http://www.ccdc.cam.ac.uk/)

Experimental procedures

All experimental procedures are arranged in the ascending order of numbers of the compounds

65.6 mmol) in 30 mL of acetic acid was added over 30 min to a solution of 2,4-dihydroxyacetophenone (2-5) (9.5 g, 62.5 mmol) in 77 mL of glacial acetic acid After 4 h, the reaction was quenched by addition of a saturated solution of sodium thiosulfate The aqueous layer was extracted 4 times and the combined organic layers were washed four times with water, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (hexane/EtOAc, 8/2)

to afford compound 3-11 (8.688 g, 50%) as a clear oil IR (KBr): νmax = 3291, 2917, 2735,

1636, 1615, 1270 cm-1; 1 H NMR (300 MHz, CDCl3) δ 12.48 (s, 1 H), 8.02 (s, 1H), 6.59 (s, 1 H), 2.56 (s, 3H); 13 C NMR (75 MHz, CDCl3) δ 201.69, 165.21, 160.87, 140.76, 116.82,

103.56, 73.44, 26.25; EIMS +: m/z (%): 278 (80) [M]+, 263 (100), 136 (25), 108 (12), 41 (37);

2,4-dihydroxy-5-iodoacetophenone (3-11) (2.7 g, 9.71 mmol), p-toluenesulfonyl chloride (5.7 g, 29.90 mmol) and anhydrous K2CO3 (11.5 g, 83.21 mmol) in 150 mL

of anhydrous acetone was refluxed for 45 min The reaction mixture was cooled, filtered through Celite, washed with acetone and the filtrate was concentrated by rotary evaporation The residue was dissolved in water and extracted three times with 200 mL of DCM The

combined organic layers were washed with 70 mL of 1M HCl, water, and brine The organic layer was dried over Na2SO4 and concentrated via rotary evaporation The resulting crude

product was purified by flash column chromatography (5:1 hexane/EtOAc) to afford compound 3-2 in 94% yield (5.3 g, 8.66 mmol) as white crystals IR (KBr): νmax = 2960,

100 mL of Et2O and treated slowly with 30 mL of saturated NH4Cl The organic layer was collected and the aqueous layer was washed twice with 100 mL of Et2O The combined organic layers were extracted sequentially with 30 mL of saturated NH4Cl, water and brine, dried over Na2SO4 and the solvent was removed on a rotary evaporator at < 23 °C (note: the product is highly volatile) The resulting brown oil was dissolved in anhydrous DMF NaH

(0.6 g 15 mmol) was added to this solution in portions After 15 min, n-Bu4NI (0.369 g, 1 mmol) and benzyl bromide (1.7 g, 10.0 mmol) were added sequentially After 18 h, the solvent was removed on a rotary evaporator at 40 °C The crude product was dissolved in water and extracted three times with 70 mL of Et2O The combined organic layers were

OBn

3-3

washed with 50 mL of 1M HCl, water and brine, dried over Na2SO4 and concentrated via

rotary evaporation The crude product was purified by flash chromatography (98:2 hexane/EtOAc) to afford intermediate 3-3 as a viscous colourless oil, which crystallised after

storage for 24 h at -20 °C giving white crystals in 27% yield (0.501 g, 2.72 mmol) IR (KBr):

νmax = 3281, 3246, 3007, 2861, 2116, 1378 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 7.41-7.28 (m, 5H), 4.78 (s, 2H), 2.60 (s, 2H), 1.85 (s, 3H); 13 C-NMR (125 MHz, CDCl3) δ 137.82,

128.33, 128.09, 127.68, 82.42, 72.56, 68.37, 30.74; EIMS+: m/z (%): 153 (65), 141 (20), 91

(100), 77 (63); HRMS (EI) m/z: 183.0808 [calcd [M–H]ˉ of 184.0888 for C13H12O]

For synthetic intermediate 3-3, a small colourless block, 0.8 x 0.64 x 0.16 mm, was used for X-ray crystallographic data collection at 223(2) K using Mo (Kα) radiation 7372 reflections

were collected and 2458 were unique (R int = 0.0271) No symmetry higher than monoclinic was observed and the centrosymmetric alternative, P21/c, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were refined anisotropically All H atoms were placed in idealized locations For C13H12O, monoclinic, P21/c, a = 12.5415(10), b = 6.7365(5), c = 13.0122(11) Å, α = 90, β = 102.770(2),

γ = 90 °, V = 1072.15(15) Å3, Z = 4, Dx = 1.141 Mg/m3, R1 = 0.0468, wR2 = 0.1108 based on 2σ(I) data A copy of the coordinates for structure 3-3 has been uploaded to the Cambridge Crystallographic Data Centre (http://www.ccdc.cam.ac.uk/)

The combined organic layers were washed successively with 70 mL of 1M HCl, 70 mL of water and brine, dried over Na2SO4 and evaporated under vacuum The residue was purified

by silica gel chromatography (hexane/EtOAc, 65/35 to hexane/EtOAc, 50/50) to afford compound 3-24 (8.30 g, 81%) as a yellow wax IR (NaCl): νmax = 3064, 2925, 1700, 1593,

1480, 1384, cm-1; 1 H-NMR (500 MHz, CDCl3) δ 7.77 (s, 2H), 7.71 (d, J = 8.3 Hz, 4H), 7.69 (d, J = 8.4 Hz, 4H), 7.34 (d, J = 8.3 Hz, 4H), 7.23 (d, J = 8.3 Hz, 4H), 7.14 (s, 2H), 4.77 (s,

2H), 2.50 (s, 6H), 2.47 (s, 6H), 2.36 (s, 6H), 1.85 (s, 3H); 13 C-NMR (75 MHz, CDCl3) δ 195.61, 151.85, 147.18, 146.56, 146.15, 137.66, 135.10, 134.64, 134.55, 134.46, 131.81, 131.24, 130.19, 129.97, 129.68, 128.45, 128.5, 128.25, 128.01, 127.62, 117.45, 116.02, 94.01,

mL of water and 200 mL of brine, dried over Na2SO4 and evaporated under vacuum The resulting crude product was purified by flash column chromatography (3:2 hexane/EtOAc) to afford compound 3-4 in 61% yield (2.14 g, 4.41 mmol) as a clear oil IR (NaCl): νmax = 2922,

1640, 1490, 1411, 1368, 1293 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 12.74 (s, OH, 2H), 7.80

(s, 2H), 7.40 (d, J = 7.5 Hz, 2H), 7.35 (t, J = 7.4 Hz, 2H), 7.30 (d, J = 7.4 Hz, 1H), 6.50 (s,

2H), 4.91 (s, 2H), 2.58 (s, 6H), 2.07 (s, 3H); 13 C-NMR (75 MHz, CDCl3) δ 202.6, 166.0, 163.0, 136.0, 128.7, 128.2, 128.0, 127.1, 114.8, 104.1, 103.6, 101.1, 94.1, 78.4, 68.9, 67.3,

31.5, 26.5; ESIMSˉ: m/z (%): 967 (74) [2M–H]ˉ,637 (12), 505 (28), 483 (100) [M–H]ˉ, 375 (14) [M–OBn]ˉ; HRMS (ESI) m/z: 483.1455 [calcd [M–H]ˉ of 483.1449 for C29H23O7]

Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by flash column chromatography (3:1 hexane/EtOAc) to afford 3-5 in 75% yield

(1.51 g, 3.11 mmol) as a light yellow oil IR (NaCl): νmax = 3435, 2927, 1645, 1448, 1371,

(154 µ L, 0.154 mmol) was added to 3-5 (50 mg, 0.103 mmol) in 5 mL of anhydrous DCM at -78 °C The reaction mixture was stirred at this temperature for 15 min The

reaction was terminated by the addition of 5 mL of water and slowly warmed to 23 °C over 1.5 h The reaction mixture was extracted three times with 10 mL of DCM The combined organic layers were washed with 10 mL of 5% NaHCO3, water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5

µm with a gradient: 10 to 100% CH3CN in 30 min to afford iso-laetirobin A (3-26) in 24%

yield, as a yellow-brown oil (9.5 mg, 0.013 mmol) IR (NaCl): νmax = 3434, 1638, 1452,

1355, 1241 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 12.86 (s, 1H), 12.57 (s, 1H), 12.55 (s, 1H), 12.39 (s, 1H), 7.92 (s, 1H), 7.89 (s, 1H), 7.85 (s, 1H), 7.27 (s, 1H), 7.01 (s, 1H), 6.77 (s, 1H),

6.57 (s, 1H), 6.30 (s, 1H), 6.28 (s, 1H), 6.19 (s, 1H), 4.80 (s, 1H), 4.18 (d, J = 18.0 Hz, 1H), 3.68 (d, J = 18.0 Hz, 1H), 2.73 (s, 3H), 2.67 (s, 3H), 2.63 (s, 3H), 2.01 (d, J = 2.0 Hz, 3H)

1.63 (s, 3H); 13 C-NMR (125 MHz, CDCl3) δ 204.19, 204.13, 204.04, 202.66, 165.92, 163.83, 161.45, 158.59, 155.64, 153.47, 150.83, 127.83, 124.30, 123.70, 120.16, 116.86, 115.07, 110.14, 105.28, 105.20, 100.32, 99.97, 99.80, 98.82, 47.53, 27.20, 27.15, 27.05, 25.27, 11.69;

for C44H32O12]

Crystals were obtained upon recrystallisation from a dichloromethane/methanol mixture For synthetic intermediate 3-26, a small block, 0.40 x 0.20 x 0.18 mm, was used for X-ray crystallographic data collection at 223(2) K using Mo (Kα) radiation 12405 reflections were

collected and 8291 were unique (R int = 0.0276) No symmetry higher than triclinic was observed and the centrosymmetric alternative, Pī, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were refined anisotropically All H atoms were placed in idealized locations For C44H32O12,

triclinic, Pī, a = 11.9232(17), b = 12.0133(16), c = 13.613(2) Å, α = 97.200(3), β = 109.150(3), γ = 90.874(3) °, V = 1824.1(4) Å3, Z = 2, Dx = 1.400 Mg/m3, R1 = 0.0759, wR2 =

0.2006 based on 2σ(I) data A copy of the coordinates for structure 3-26 has been uploaded to the Cambridge Crystallographic Data Centre (http://www.ccdc.cam.ac.uk/)

bis-benzo[b]furan 3-5 (797.0 mg, 1.645 mmol) was dissolved in

50 mL of a mixture of 5% MeOH in DCM Subsequently, 0.5 mL of 1% aqueous 1.0 M HCl was added and the mixture was stirred for 30 h at 23 °C and under ambient atmosphere The reaction mixture was poured into 30 mL saturated sodium bicarbonate solution and extracted three times with 20 mL of DCM The combined organic layers were washed with 20 mL water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm with a gradient: 10 to 100% CH3CN in 30 min to afford synthetic laetirobin A (2-1 ) in 64% yield (399 mg, 0.530 mmol) as a light yellow solid IR (KBr): νmax = 3516, 2925, 1644, 1465,

1369, 1254 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 12.45 (s, OH, 2H), 12.44 (s, OH, 1H), 12.37 (s, OH, 1H), 7.92 (s, 1H), 7.91 (s, 1H), 7.90 (s, 1H), 7.68 (s, 1H), 7.00 (s, 1H), 6.96 (s, 1H),

6.96 (s, 2H), 6.57 (s, 1H), 6.48 (s, 1H), 6.47 (s, 1H), 6.47 (s, 1H), 4.47 (t, J = 5.5 Hz, 1H),

2.76 (m, 1H), 2.69 (m, 1H), 2.66 (s, 3H), 2.65 (s, 6H), 2.36 (m, 1H), 2.35 (s, 3H), 2.32 (m,

159.8, 159.7, 159.7, 159.6, 158.7, 158.2, 157.3, 153.7, 144.7, 123.9, 123.9, 123.6, 123.3, 121.2, 120.8, 120.7, 119.5, 117.4, 117.2, 117.2, 115.9, 106.0, 105.6, 104.4, 100.4, 100.1,

100.1, 100.0, 43.5, 34.7, 31.3, 27.1, 27.1, 27.1, 26.9, 25.5; EIMSˉ: m/z (%): 751 (33) [M–H]ˉ;

Crystals were obtained upon recrystallisation from a dichloromethane/methanol mixture For

synthetic laetirobin A ( 2-1 ), a small orange block, 0.16 x 0.10 x 0.08 mm, was used for X-ray

2-1

O O

O

O

O O

4-38

O O

crystallographic data collection at 223(2) K using Mo (Kα) radiation 14236 reflections were

collected and 9076 were unique (R int = 0.0342) No symmetry higher than triclinic was observed and the centrosymmetric alternative, Pī, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were refined anisotropically All H atoms were placed in idealized locations For C44H32O12,

triclinic, Pī, a = 10.9989(12), b = 13.8100(14), c = 14.2340(15) Å, α = 112.139(2), β = 90.723(3), γ = 94.576(3) °, V = 1994.1(4) Å3, Z = 2, Dx = 1.452 Mg/m3, R1 = 0.0709, wR2 = 0.1967 based on 2σ(I) data A copy of the coordinates for structure 2-1 has been uploaded to the Cambridge Crystallographic Data Centre (http://www.ccdc.cam.ac.uk/)

Ethyl hydroxybenzofuran-2-yl)-7-hydroxy-1,2,3,9b-tetra- hydrodibenzo[b,d]furan-1-yl)benzofuran-6-yloxy)

mmol) and dry K2CO3 (19.0 mg, 0.014 mmol) were dissolved in 2 mL of anhydrous DMF under an inert atmosphere of argon Subsequently, ethyl bromoacetate (4-32) (2.3 mg, 0.014 mmol dissolved in 410 µl of

anhydrous DMF) was added via syringe pump (1 mL/h) to the reaction mixture After being

stirred for 5 h at 23 °C, the reaction mixture was poured into 10 mL of water and extracted three times with 5 mL of EtOAc The combined organic layers were washed with 10 mL water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by flash column chromatography (3:2 hexane/EtOAc) to obtain a compound 4-38 enriched crude product Consecutive preparative TLC purification steps (2:1 hexane/EtOAc, 2x developed followed by 3:2 hexane/EtOAc, 3x developed) was conducted to afford 4-38 in 27% yield (3.0 mg, 0.004

O O

O

O

O O

2.38-2.33 (m, 4H), 1.33-1.29 (m, 4H) (Note: inseparable mixture of either diastreomers or two

differently mono-labelled compounds); HRMS (EI) m/z: 839.2318 [calcd [M+H]+ of 839.2340 for C48H39O14]

2-(5-acetyl-2-((9bS)-8-acetyl-1,4-bis(5-acetyl-6-hydroxy benzofuran-2-yl)-7-hydroxy-1,2,3,9b-tetrahydrodi- benzo[b,d]furan-1-yl)benzofuran-6-yloxy)-N-(2-(2-(7- (dimethylamino)-2-oxo-2H-chromen-4-yl)acetamido)-

and LiOH (1.0 mg, 0.021 mmol) were dissolved in 9 mL

of a mixture of EtOH and water (2/1) under an inert atmosphere of argon The reaction mixture was stirred for 18 h at 23 °C and poured into 10

mL of water The pH value of the mixture was adjusted to 1 using 1M HCl before extraction with 5 mL of EtOAc (three times) The combined organic layers were washed with 10 mL water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude acid 4-39 was dried on the high vacuum overnight Subsequently, amine 4-42·TFA (4.2 mg, 0.015 mmol), HATU (4.2 mg, 0.011 mmol) and

HOAt (1.6 mg, 0.011 mmol) were added to the crude acid which was dissolved in 1 mL of DCM under an inert atmosphere of argon prior to the addition of reagents After the addition

of triethylamine (200 µl), the reaction mixture was stirred for 18 h at 23 °C and poured into

10 mL of water The pH value of the mixture was adjusted to 1 using 1M HCl before extraction with 5 mL of DCM (three times) The combined organic layers were washed with

10 mL water and brine The organic layer was dried over Na2SO4 and the solvent was

removed on a rotary evaporator The resulting crude amide was purified by flash column chromatography (2:3 hexane/EtOAc) to obtain a compound 4-43 enriched crude product Consecutive preparative TLC purification steps (2:1 hexane/EtOAc, 3x developed followed

by 99:1 DCM/MeOH, 3x developed) was conducted to afford 4-43 in 27% yield (3.0 mg,

0.004 mmol) as a light yellow solid HRMS (EI) m/z: 1082.2229 [calcd [M+H]+ of 1082.3338 for C61H52O16N3] ) (Note: inseparable mixture of either diastreomers or two

differently mono-labelled compounds)

benzo[b]-furan 3-49 (100 mg, 0.85 mmol) in freshly distilled THF (3 mL) was added to a solution of n-butyllithium (0.6 mL of a 1.6 M solution in hexane, 0.94 mmol) in THF (3 mL) at -78 ºC After being stirred at -78 ºC for 1 h, the solution

was transferred via cannula to a solution of 2-acetylbenzo[b]furan 5-1 (136.0mg, 0.85 mmol)

in THF (6 mL) cooled to -78 ºC After being stirred for 2 h at -78 ºC, the reaction mixture was poured into water The aqueous layer was extracted three times with 15 mL of Et2O The combined organic layers were washed with 10 mL water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm with a gradient: 10 to 100% CH3CN in 30 min to afford 5-2 in 41% yield (97 mg, 0.35 mmol)

as a white solid IR (KBr): νmax = 3387, 3063, 1450, 1373, 1250 cm-1; 1 H-NMR (300 MHz,

1,1,4-tri(benzo[b]furan-2-yl)-1,2,3,9b-tetrahydroidbenzo[b,d]-

mmol) in freshly distilled THF (4 mL) was added Burgess

reagent (77.0 mg, 0.324 mmol) The reaction mixture was stirred under an inert atmosphere of argon for 20 h The reaction was poured into 20 mL of water and extracted three times with 10 mL of Et2O The combined organic layers were washed with 10

mL of water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm with a gradient: 10 to 100% CH3CN

in 30 min to afford 5-4 in 89% yield (25 mg, 0.048 mmol) as a white solid IR (NaCl) νmax =

3064, 2892, 1691, 1594, 1457, 1241 cm-1; 1 H-NMR (300 MHz, CDCl3) δ 7.52 (m, 3H), 7.39

(m, 2H), 7.31 (m, 3H), 7.19 (m, 4H), 7.11 (m, 1H), 7.05 (s, 1H), 6.87 (t, J = 7.40 Hz, 1H), 6.70 (d, J = 7.38 Hz, 1H), 6.36 (s, 1H), 5.97 (s, 1H), 5.26 (s, 1H), 2.87 (m, 4H); 13 C-NMR

(125 MHz, CDCl3) δ 159.42, 158.10, 155.06, 155.03, 154.19, 153.80, 153.25, 151.98, 129.50, 129.03, 128.39, 128.12, 124.42, 123.22, 122.83, 121.34, 121.29, 120.66, 111.49, 111.23,

111.01, 110.55, 106.10, 104.92, 103.99, 99.99, 49.34, 45.07, 33.33, 22.61; ESIMS +: m/z (%):

559 (15) [M+K]+, 543 (60) [M+Na]+, 521 (100) [M+H]+, 419 (11), 261 (13) [M/2+H]+;

Crystals were obtained upon recrystallisation from a dichloromethane/methanol mixture For the [4+2]-cycloadduct 5-4, a small colourless block, 0.48 x 0.12 x 0.08 mm, was used for X-ray crystallographic data collection at 223(2) K using Mo (Kα) radiation 18023 reflections

were collected and 5865 were unique (R int = 0.0421) No symmetry higher than monoclinic was observed and the centrosymmetric alternative, P21/c, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were

O

O

O O

H

5-4

refined anisotropically All H atoms were placed in idealized locations For C36H24O4, monoclinic, P21/c, a = 10.0478(6), b = 28.418(2), c = 9.3323(6) Å, α = 90, β = 105.343(2), γ =

90 °, V = 2569.7(3) Å3, Z = 4, Dx = 1.346 Mg/m3, R1 = 0.0626, wR2 = 0.1441 based on 2σ(I) data A copy of the coordinates for structure 5-4 has been uploaded to the Cambridge Crystallographic Data Centre (http://www.ccdc.cam.ac.uk/)

µ L, 0.320 mmol) was added to 5-2 (60 mg, 0.216 mmol) in 5 mL of anhydrous DCM at -78 °C The deep purple reaction mixture was stirred at this temperature for 15 min The reaction was terminated by the addition of 10 mL of water and slowly warmed to 23 °C over 1.5 h The reaction mixture was extracted three times with 10 mL of DCM The combined organic layers were washed with 10 mL of 5% NaHCO3, water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator After silica gel chromatography 18.0 mg of a yellow powder (32%, 0.035 mmol) of the [5+2] cycloadduct 5-6 was isolated For unambiguous structure determination, 13.0 mg of this material was further purified by preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm column with a gradient:

10 to 100% CH3CN in 30 min to afford 4.7 mg of 5-6 as a light yellow solid IR (NaCl) νmax

110.14, 109.55, 106.74, 104.95, 103.72, 52.64, 47.66, 34.66, 29.93, 11.77, 11.76; ESIMS +:

O

O

O O

H

5-6

m/z (%): 591 (57), 575 (100), 570 (24), 535 (31), 519 (71) [M–H]+, 419 (27), 247 (20);

Crystals were obtained upon recrystallisation from a dichloromethane/methanol mixture For the [5+2]-cycloadduct 5-6, a small colourless block, 0.32 x 0.18 x 0.08 mm, was used for X-ray crystallographic data collection at 223(2) K using Mo (Kα) radiation 16383 reflections

were collected and 5751 were unique (R int = 0.0241) No symmetry higher than triclinic was observed and the centrosymmetric alternative, Pī, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were refined anisotropically All H atoms were placed in idealized locations For C36H24O4, triclinic, Pī, a = 9.6753(4), b = 11.4318(5), c = 12.7153(5) Å, α = 72.7480(10), β = 79.5670(10), γ = 69.6640(10) °, V = 1254.61(9) Å3, Z = 2, Dx = 1.378 Mg/m3, R1 = 0.0454, wR2 = 0.1130 based on 2σ(I) data A copy of the coordinates for structure 5-6 has been uploaded to the Cambridge Crystallographic Data Centre (http://www.ccdc.cam.ac.uk/)

(2.72 g, 20.0 mmol) was dissolved in 20 mL of THF/H2O (50/50, v/v) Iodine (5.6 g, 22.0 mmol) and NaHCO3 (1.84 g, 22.0 mmol) were crushed and mixed together and added to the solution After the mixture was stirred for 18 h at room temperature, residual iodine was quenched by addition of a 5% aqueous solution of sodium thiosulfate The aqueous layer was extracted three times with Et2O (50 mL each) and the combined organic layers were washed with saturated sodium thiosulfate solution (30 mL), water (30 mL), brine (50 mL), dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (DCM/MeOH, 95/5) to afford compound

5-8 in 19% yield (1.010 g, 3.82 mmol) as a clear oil IR (NaCl): νmax = 3124, 2916, 1651,

of Et2O The combined organic layers were washed with 20 mL of 1M HCl, water, and brine The organic layer was dried over Na2SO4 and concentrated via rotary evaporation The

resulting crude product was purified by flash column chromatography (hexane to hexane/EtOAc, 4/1) to afford compound 5-9 in 80% yield (1.30 g, 3.05 mmol) as colourless

oil that solidified upon drying in high vacuum IR (NaCl): νmax = 3062, 2924, 1689, 1589,

1473, 1381, 1242, 1180, 1095, 1033 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 8.32 (d, J = 2.55

Hz, 1H), 7.91 (dd, J = 2.55, 8.8 Hz, 1H), 7.81 (d, J = 8.2 Hz, 2H), 7.44 (d, J = 8.8 Hz, 1H), 7.35 (d, J = 8.2 Hz, 2H), 2.57 (s, 3H), 2.46 (s, 3H); 13 C-NMR (125 MHz, CDCl3) δ 195.35, 153.28, 146.14, 140.22, 136.54, 132.54, 129.95, 129.62, 128.81, 122.68, 90.48, 26.54, 21.78;

(5-9) (1.25 g, 3.0 mmol), bis

mmol), palladium dichloride (32.0

in a mixture of degassed DMF/triethylamine (5

mmol), bis-acetylene 3-3 (0.276 g, 1.5 mmol), PPhmmol), palladium dichloride (32.0 mg, 0.180 mmol), cuprous iodide (34.3

in a mixture of degassed DMF/triethylamine (5 mL/15 mL) was heated to 80

HCl (100 mL), the mixture was extracted three times with 50 The combined organic layers were washed successively with 1M

mL).The organic layer was dried over Na2SO4vacuum The residue was purified by silica gel chromatography (hexane/

, 50/50) to afford 5-10 (0.87 g, 76%) as a clear oil Fractions containing were stored in the dark for several days which lead to colourless crystals of

6%) For 5-10 IR (NaCl): νmax = 3062, 3001, 2931,

1597, 1489, 1381, 1265, 1180, 1095, 1026 cm-1; 1 H-NMR (500 MHz, CDCl

= 1.9, 8.2 Hz, 2H), 7.78 (m, 4H), 7.44 (m, 2H), 7.37 (m, 4H), 7.29 (m,

4 (m, 4H), 4.84 (s, 2H), 2.59 (s, 6H), 2.34 (s, 6H), 1.91 (s, 3H);

195.94, 153.01, 145.87, 137.94, 135.35, 134.26, 132.29, 129.89, 129.77, 128.54, 128.29, 128.14, 127.62, 122.48, 117.44, 93.57, 78.56, 68.72, 66.74, 30.48, 26.58, 21.60;

mmol), PPh3 (94.4 mg, 0.360

(34.3 mg, 0.180 mmol) ) was heated to 80 °C for 4 h ), the mixture was extracted three times with 50 mL

1M HCl (50 mL), water and evaporated under purified by silica gel chromatography (hexane/EtOAc, 65/35 to

Fractions containing were stored in the dark for several days which lead to colourless crystals of

= 3062, 3001, 2931, 2870, 1689, (500 MHz, CDCl3) δ 8.09 (d, J =

= 1.9, 8.2 Hz, 2H), 7.78 (m, 4H), 7.44 (m, 2H), 7.37 (m, 4H), 7.29 (m,

4 (m, 4H), 4.84 (s, 2H), 2.59 (s, 6H), 2.34 (s, 6H), 1.91 (s, 3H); 13 C-NMR (125 MHz,

195.94, 153.01, 145.87, 137.94, 135.35, 134.26, 132.29, 129.89, 129.77, 128.54, 128.29, 128.14, 127.62, 122.48, 117.44, 93.57, 78.56, 68.72, 66.74, 30.48, 26.58, 21.60;

m/z: 783.1731 [calcd

7.61 (s, 1H), 7.60 (s, 1H), 7.51 (m, 12H), 7.31 (m, 6H), 7.20 (m, 13H), 7.16 (s, 1H), 7.14 (m, 1H), 6.89

= 8.2 Hz, 1H), 2.43 (s, 3H), 2.11 (s, 196.98, 155.32, 153.44, 153.18, , 139.10, 135.01, 134.96, 134.92, 134.66, 134.30, 133.39, 131.98, 131.79, 131.60, 129.93, 129.74, 128.27, 127.99, 127.86, 127.83, 127.78,

OBn OH

O

OH O

5-11

Crystals were obtained upon recrystallisation from a hexane/ethylacetate mixture For the side product 5-14, a small colourless block, 0.28 x 0.12 x 0.10 mm, was used for X-ray crystallographic data collection at 100(2) K using Mo (Kα) radiation 30598 reflections were

collected and 10023 were unique (R int = 0.0409) No symmetry higher than monoclinic was observed and the centrosymmetric alternative, P21/n, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were refined anisotropically All H atoms were placed in idealized locations For C51H43IO4P2PdS, monoclinic, P21/n, a = 17.2514(6), b = 11.3058(4), c = 23.7741(9) Å, α = 90, β = 108.9530(10), γ = 90 °, V = 4385.5 Å3, Z = 4, Dx = 1.586 Mg/m3, R1 = 0.0507, wR2 = 0.1127 based on 2σ(I) data

1,1'-(3,3'-(3-(benzyloxy)-3-methylpenta-1,4-diyne-1,5-diyl)-

re-liability, magnesium turnings were activated by stirring them over 1M HCl for 5 minutes, filtering, washing with acetone and

Et2O, and drying under high vacuum for 2 hours A solution of compound 5-10 (0.796 g, 1.05 mmol) and freshly activated magnesium turnings (0.510 g, 20.98 mmol) in 50 mL of MeOH was stirred for 18 h After addition of 50 mL of 10% citric acid, the mixture was extracted three times with 30 mL of EtOAc The combined organic layers were washed twice with 20

mL of 10% citric acid, 20 mL of water and 20 mL of brine, dried over Na2SO4 and evaporated under vacuum The resulting crude product was purified by flash column chromatography (3/1 hexane/EtOAc to 3/2 hexane/EtOAc) to afford compound 5-11 in 51% yield (0.253 g,

0.56 mmol) as a clear oil IR (NaCl) νmax = 2922, 1640, 1490, 1411, 1368, 1293 cm-1; 1

5H), 7.00 (d, J = 8.85 Hz, 2H), 4.92 (s, 2H), 2.56 (s, 6H), 2.08 (s, 3H); 13 C-NMR (125 MHz,

CDCl3) δ 195.92, 160.77, 137.51, 133.38, 131.65, 130.29, 128.54, 128.49, 128.42, 128.00,

127.85, 115.30, 108.53, 95.25, 78.51, 68.87, 67.08, 31.17, 26.32; ESIMSˉ: m/z (%): 903 (100) 565 (57), 451 (61); HRMS (ESI) m/z: 453.1712 [calcd [M+H]+ of 453.1702 for

C29H25O5]

1,1'-(2,2'-(1-(benzyloxy)ethane-1,1-diyl)bis(benzofuran-5,2-

mg, 0.38 mmol), cuprous iodide (18.0 mg, 0.095 mmol) and triethylamine (425.0 mg, 4.20 mmol) in 5 mL of DMF was heated at 60˚C for 2 hours The reaction mixture was poured into 10 mL saturated aqueous

NH4Cl solution and extracted three times with 10 mL of Et2O The combined organic layers were washed with 10 mL of 1M HCl, saturated NaHCO3, water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by flash column chromatography (hexane to 3/1 hexane/EtOAc) to afford 5-12 in 49% yield (83 mg, 0.18 mmol) as a colourless oil IR (NaCl): νmax = 2916,

2854, 1681, 1589, 1435, 1357, 1265, 1118, 1056, 1026 cm-1; 1 H-NMR (500 MHz, CDCl3) δ

8.23 (d, J = 1.9 Hz, 2H), 7.96 (dd, J = 1.9, 8.85 Hz, 2H), 7.51 (d, J = 8.85 Hz, 2H), 7.32 (m,

5H), 6.95 (s, 2H), 4.54 (s, 2H), 2.66 (s, 6H), 2.17 (s, 3H); 13 C-NMR (125 MHz, CDCl3) δ 197.48, 158.72, 157.50, 137.97, 133.00, 128.36, 128.03, 127.63, 127.43, 125.35, 122.62,

111.53, 105.82, 75.11, 66.72, 26.76, 23.48; ESIMS +: m/z (%): 927 (72) [2M+Na]+, 344 (66) [M–OBn]+, 167 (100); HRMS (ESI) m/z: 453.1682 [calcd [M+H]+ of 453.1702 for

mmol) was dissolved in 10 mL of a mixture of 5% MeOH in DCM Subsequently, 0.1 mL of 1% aqueous 1M HCl was added and the mixture was stirred for 5 days at 23 °C under ambient atmosphere The reaction mixture was poured into 10 mL saturated aqueous sodium bicarbonate solution and extracted three times with 10 mL of DCM The combined organic layers were washed with 10 mL water and brine The organic layer was dried over Na2SO4

and the solvent was removed on a rotary evaporator The resulting crude product was first purified by preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm with a gradient: 10 to 100% CH3CN in 30 min, followed by preparative thin layer chromatography and a final preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm with a gradient: 10 to 100% CH3CN in 30 min to afford compound 5-13 in 7% yield (3.5 mg, 0.005 mmol) as a colourless oil IR (KBr): νmax = 3055, 2916, 2849, 1674, 1585, 1439, 1362, 1300,

1267, 1155, 810, 739 cm-1; 1H-NMR (500 MHz, CDCl3) δ 8.18 (m, 3H), 7.95 (m, 5H), 7.51

(m, 4H), 6.71 (s, 1H), 6.65 (s, 1H), 6.64 (s, 1H), 4.63 (t, J = 5.7 Hz, 1H), 2.92 (m, 1H), 2.83

(m, 1H), 2.65 (s, 3H), 2.64 (s, 6H), 2.41 (s, 3H);EIMSˉ: m/z (%): 687 (100) [M–H]ˉ; HRMS

(ESI) m/z: 689.2149 [calcd [M+H]+ of 689.2175 for C44H33O8]

13 mL of Et2O was added over 30 min to a stirring solution of resorcinol (

5-15) (1.36 g, 12.35 mmol) in 14 mL of Et2O After 1 h, the reaction was quenched by addition of a saturated solution of sodium thiosulfate The aqueous layer was extracted with 3 x 30 mL Et2O The combined organic layers were washed 3 times with a saturated solution of sodium thiosulfate, water, and brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (9/1 CHCl3/acetic acid) to afford compound 5-16 as a colourless oil in 25% yield (0.730 g, 3.09 mmol) 1 H NMR (500 MHz, CDCl3) δ 7.45 (d, J = 8.8 Hz, 1 H), 6.54 (d, J = 3.15 Hz, 1 H),

6.27 (dd, J = 3.15, 8.8 Hz, 1H), 5.15 (bs, 1H); 13 C NMR (125 MHz, CDCl3) δ 157.68, 155.70, 138.31, 110.43, 102.65, 74.49

4-iodobenzene-1,3-diol (5-16) (0.730 g, 3.09 mmol), p-toluenesulfonyl chloride (1.77 g, 9.28 mmol) and anhydrous K2CO3 (3.42 g, 24.74 mmol) in

40 mL of anhydrous acetone was refluxed for 1.5 hours The reaction mixture was cooled, filtered through Celite, washed with acetone and the filtrate was concentrated by rotary evaporation The residue was dissolved in water and extracted three times with 20 mL of

Et2O The combined organic layers were washed with 30 mL of 1M HCl, water, and brine The organic layer was dried over Na2SO4 and concentrated via rotary evaporation The

resulting crude product was purified by flash column chromatography (from 100% hexane to 8/2 hexane/EtOAc) to afford compound 5-18 in 89% yield (1.42 g, 2.61 mmol) as a white

solid IR (NaCl): νmax = 3062, 2924, 1597, 1465, 1381, 1188, 1111, 1026, 964 cm-1; 1 H-NMR

(500 MHz, CDCl3) δ 7.73 (dd, J = 8.2, 8.2 Hz, 4H), 7.67 (d, J = 8.2 Hz, 1H), 7.34 (dd, J = 8.2, 8.2 Hz, 4H), 6.97 (d, J = 2.5 Hz, 1H), 6.74 (dd, J = 2.5, 8.2 Hz, 1H), 2.46 (s, 6H); 13 C-

129.92, 128.83, 128.49, 122.48, 117.50, 88.18, 21.78, 21.75; EIMS +: m/z (%): 561 (100)

[M+NH4]+; HRMS (ESI) m/z 566.9488 [calcd [M+Na]+ of 566.9409 for C20H17O6INaS2]

dihydroxy-benzene 5-18 (1.4 g, 2.57 mmol), acetylene derivative 3-3

(0.240 g, 1.30 mmol), PPh3 (82.2 mg, 0.313 mmol), palladium dichloride (28.0 mg, 0.158 mmol), cuprous iodide (30.0 mg, 0.158 mmol) in a mixture of degassed DMF/triethylamine (5 mL/15 mL) was heated to 80 ˚C for 4 h After

OTs

I

5-18

TsO

addition of 1M HCl, the mixture is extracted three times with 80 mL EtOAc The combined organic layers were washed successively with 50 mL of 1M HCl, 50 mL of water and brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel chromatography (hexane/EtOAc, 65/35 to hexane/EtOAc, 50/50) to afford compound 5-19 in

51% yield (0.680 g, 0.669 mmol) as a yellow wax IR (NaCl): νmax = 3062, 2924, 1597, 1489,

1381, 1188, 1087, 964 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 7.70 (m, 8H), 7.34 (m, 11H),

7.23 (m, 4H), 6.97 (d, J = 1.9 Hz, 2H), 6.91 (dd, J = 1.9, 8.2 Hz, 2H), 4.77 (s, 2H), 2.45 (s,

6H), 2.36 (s, 6H), 1.86 (s, 3H); 13 C-NMR (125 MHz, CDCl3) δ 150.17, 149.62, 146.03, 145.85, 137.97, 134.32, 132.14, 131.78, 130.04, 129.89, 128.60, 128.48, 128.32, 128.11,

127.63, 120.99, 117.16, 116.12, 93.59, 78.28, 68.65, 66.74, 30.50, 21.75, 21.66; ESIMS +: m/z

(%): 1039 (36) [M+Na]+, 1034 (100) [M+NH4]+, 500 (63), 352 (38); HRMS (ESI) m/z

1034.2034 [calcd [M+NH4]+ of 1034.2008 for C53H48O13NS4]

neat mixture of 2-hydroxy-4-methoxy-benzaldehyde (

3-39) (300 mg, 1.97 mmol) and 1,3-dichloroacetone (3-30) (125 mg, 0.98 mmol) was heated at 60˚C At approximately 45 °C, the solid starting materials started to melt After 1 hour, freshly dried and grinded potassium phosphate (879 mg, 4.14 mmol) was added to reaction mixture and the mixture was heated to 80 °C for further 3 hours The brown powder formed was subsequently transferred into an Erlenmeyer flask containing DCM (30 mL) and water (50 mL) The obtained suspension was stirred for 30 minutes and transferred into a separating funnel The aqueous phase was extracted two more times with 30

mL of DCM The combined organic layers were washed twice with 30 mL of water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by flash column chromatography (4:1 hexane/EtOAc

to 1:1 hexane/EtOAc) to afford 3-40 in 36% yield (115 mg, 0.36 mmol) as a yellow solid IR

3-40 (20.0 mg, 0.06 mmol) in 2 mL of freshly distilled THF was added methyl magnesiumbromide (11 mg, 0.09 mmol, 3.0M in Et2O) at 0 °C After 0.5 hours, the ice bath was removed and the mixture was stirred for 3.5 h at 23 °C under an inert atmosphere of argon The reaction mixture was poured into 10 mL saturated NH4Cl solution and extracted three times with 10 mL of Et2O The combined organic layers were washed with 10 mL water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude material (31 mg) was not purified as the obtained product looked unstable since the colour changed from yellow to dark blue when evaporated to dryness

It should be noted that all calculations are based on the theoretical yield of the previous

reaction To a solution of tert-alcohol 5-21 (31.0 mg, 0.092 mmol) in freshly distilled THF (3

mL) was added Burgess reagent (44.0 mg, 0.185 mmol) The reaction mixture was stirred under an inert atmosphere of argon for 20 h The reaction was poured into 15 mL of water and extracted three times with 10 mL of Et2O The combined organic layers were washed with 10

mL of water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by preparative

HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm with a gradient: 10 to 100% CH3CN

in 30 min Aliquots of the obtained fractions were screened for the desired product by HRMS The product was lyophilised in the dark The product obtained, however, decomposed

HPLC-during the drying process HRMS (taken from preparative HPLC fraction) (ESI) m/z:

641.2183 [calcd [M+H]+ of 641.2175 for C40H33O8]

suspension of ketone 3-40 (40 mg, 0.124 mmol) in NMP (220

(4.0 mg, 0.025 mmol) The mixture was heated at 210 ˚C for 4 hours At approximately 100

°C, a clear, dark red solution was formed The reaction mixture was cooled down and poured into 20 mL of 1M HCl The aqueous acidic phase was extracted three times with 15 mL of EtOAc The combined organic layers were washed with 20 mL of 1M HCl, 20 mL of water and brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel chromatography (3:2 hexane/EtOAc to 1:1 hexane/EtOAc) to afford compound 5-23

in 94% yield (34 mg, 0.117 mmol) as a brown solid IR (NaCl): νmax = 2955, 2918, 2848,

0.294 mmol, 3.0M in Et2O) at 0 °C After 0.5 hours, the ice bath was removed and the mixture was stirred for 3.5 h at 23 °C under an inert atmosphere of argon The reaction mixture was poured into 10 mL saturated NH4Cl solution and extracted three times with 10

mL of Et2O The combined organic layers were washed with 10 mL water and brine The organic layer was dried over Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude material was not purified as the obtained product looked unstable since the colour changed from yellow to dark blue when evaporated to dryness

It should be noted that all calculations are based on the theoretical yield of the previous

reaction Tert-alcohol 5-24 (26.0 mg, 0.084 mmol) was dissolved in 10 mL of a mixture of

5% of MeOH in DCM Subsequently, 0.1 mL of 1M aqueous HCl was added and the mixture was stirred for 13 hours at 23 °C and under ambient atmosphere The reaction mixture was poured into 10 mL saturated aqueous sodium bicarbonate solution and extracted three times with 10 mL of DCM The combined organic layers were washed with 10 mL water and brine The resulting crude product was purified by preparative HPLC on a Waters SunFire C18 OBD 19x50 mm, 5 µm with a gradient: 10 to 100% CH3CN in 30 min Aliquots of the obtained fractions were screened for the desired product by HPLC-HRMS However, the only product

obtained seemed to be oxidized as the mass was short of 2 Daltons HRMS (taken from

preparative HPLC fraction) (ESI) m/z: 583.1427 [calcd [M+H]+ of 585.1549 for C36H25O8]

4-acetyl-6-((triethylsilyl)ethynyl)-1,3-phenylene-bis(4-methyl-

6.82 mmol), acetylene derivative 3-36 (1.15 g, 8.19 mmol), PPh3(215.0 mg, 0.82 mmol), palladium dichloride (73.0 mg, 0.41 mmol), cuprous iodide (78.0 mg, 0.41 mmol) in a mixture of degassed DMF/triethylamine (8 mL/24 mL) was heated to 80 ˚C for 2.5 h After addition of 1M HCl, the mixture was extracted three times with 50 mL Et2O The combined organic layers were washed successively with 70 mL

TES OTs

TsO

O

3-56

TES OH

(NaCl): νmax = 2957, 2876, 1694, 1597, 1479, 1385, 1269, 1194, 1180, 1165, 1123, 1092,

1026, 849, 741 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 7.75 (s, 1H), 7.73 (d, J = 3.2 Hz, 2H), 7.71 (s, 2H), 7.36 (d, J = 8.2 Hz, 2H), 7.31 (d, J = 8.2 Hz, 2H), 7.11 (s, 1H), 2.51 (s, 3H), 2.47 (s, 3H), 2.45 (s, 3H), 1.00 (t, J = 7.9 Hz, 9H), 0.63 (q, J = 7.9 Hz, 6H); 13 C-NMR (125

MHz, CDCl3) δ 196.01, 152.01, 146.82, 146.55, 145.92, 135.47, 132.22, 131.76, 131.44, 130.26, 129.90, 128.60, 128.58, 117.31, 117.23, 100.30, 97.99, 30.46, 21.81, 21.75, 7.39,

4.15; ESIMS +: m/z (%): 644 (74), 621 (100) [M+Na]+; HRMS (ESI) m/z: 599.1590 [calcd

[M+H]+ of 599.1593 for C30H35O7S2Si]

For reliability, we activated our magnesium turnings by stirring over 1M HCl for 5 mins, filtering, washing with acetone and Et2O, and drying under high vacuum for 2 hours A solution of compound 3-56

(3.5 g, 5.85 mmol) and freshly activated magnesium turnings (2.85 g, 117.24 mmol) in 100

mL of MeOH were stirred for 20 h After addition of 300 mL of 10% citric acid, the mixture was extracted three times with 100 mL of EtOAc The combined organic layers were washed twice with 100 mL of water and 200 mL of brine, dried over Na2SO4 and evaporated under vacuum The resulting crude product was purified by flash column chromatography (9/1 hexane/EtOAc to 8/2 hexane/EtOAc) to afford compound 3-57 in 74% yield (1.27 g, 4.37

mmol) as a white solid IR (NaCl) νmax = 3115, 2955, 2876, 2158, 1633, 1593, 1381, 1335,

1283, 1256, 1173, 1016, 959, 856, 725 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 12.72 (s, OH,

1H), 7.78 (s, 1H), 6.50 (s, 1H), 6.33 (bs, OH, 1H), 2.57 (s, 3H), 1.06 (t, J = 7.9 Hz, 9H), 0.71 (q, J = 7.9 Hz, 6H); 13 C-NMR (125 MHz, CDCl3) δ 202.36, 165.51, 162.89, 135.02, 114.28,

20 mL of 1M HCl, saturated NaHCO3, water and brine The organic layer was dried over

Na2SO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by flash column chromatography (95/5 hexane/EtOAc) to afford compound 3-35 in

71% yield (810 mg, 2.79 mmol) as a yellow solid IR (NaCl): νmax = 3118, 2955, 2876, 1643,

of benzofuran 3-35 (20 mg, 0.069 mmol) and silver trifluoroacetate (32

mg, 0.145 mmol) in DCM (200 µ L) and MeOH (200 µ L) was added iodine (35 mg, 0.138 mmol) portion wise at 0 °C After 3 h, the reaction was quenched by addition of a saturated solution of sodium thiosulfate (5 mL) The aqueous layer was extracted with three times 10 mL of DCM The combined organic layers were washed twice with 5 mL

of a saturated solution of sodium thiosulfate, water, and brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography

(95/5 hexane/EtOAc) to afford compound 3-34 in 40% yield (8 mg, 0.026 mmol) as yellow

crystals IR (NaCl): νmax = 3136, 2916, 1607, 1371, 1331, 1260, 1209, 1126, 1020, 954 cm-1;

p-evaporation The resulting crude product was purified by flash column chromatography (from 100% hexane to 8/2 hexane/EtOAc) to afford compound 3-60 56% yield (80 mg, 0.175 mmol) as a white solid 1 H-NMR (300 MHz, CDCl3) δ 7.78 (s, 1H), 7.67 (d, J = 8.2 Hz, 2H), 7.31 (d, J = 8.2 Hz, 2H), 7.19 (d, J = 1.0 Hz, 1H), 6.97 (d, J = 1.0 Hz, 1H), 2.53 (s, 3H), 2.44

(s, 3H); 13 C-NMR (125 MHz, CDCl3) δ 197.40, 158.55, 146.08, 144.33, 131.61, 130.11, 129.99, 128.52, 127.93, 121.08, 117.48, 106.14, 98.82, 30.49, 21.71

A solution of bis(pinacolato)diboron (2.54 g, 10.0 mmol) and vinyl bromide (1.93 g, 3.19M in THF, 18.0 mmol) in 10 mL of a 1/1 (v/v) mixture of THF and Et2O was cooled to -115 °C using a mixture of dry ice, ethanol and liquid

N2 The clear solution was stirred for 15 minutes before freshly prepared LiTMP (1.62 g, 11.0

mmol) was added drop wise (Note: TMP was distilled just prior to use) The mixture was

gradually warmed to room temperature and stirred for 12 h The reaction mixture was quenched with saturated aq NH4Cl (50 mL), diluted with 30 mL of Et2O The organic layer was put aside and the aqueous layer was extracted two more times with Et2O (30 mL each) The combined organic layers were washed with 50 mL of water and brine The organic layer was dried over MgSO4 and the solvent was removed on a rotary evaporator The resulting crude product was purified by flash column chromatography (9:1 hexane/EtOAc) to afford 3-

38 in 24% yield (0.680 g, 2.43 mmol) as a white solid which turns into an orange wax upon storage in the freezer 1 H-NMR (400 MHz, CDCl3) δ 6.58 (s, 2H), 1.26 (s, 24H); 13 C-NMR

3-61 in 58% yield (37 mg, 0.05 mmol) as a light yellow solids IR (NaCl): νmax = 2916, 1690,

1595, 1375, 1176, 1117, 1090, 1030, 814 cm-1; 1 H-NMR (500 MHz, CDCl3) δ 7.83 (s, 2H),

7.72 (d, J = 8.2 Hz 4H), 7.34 (d, J = 8.2 Hz, 4H), 7.31 (s, 2H), 7.17 (s, 2H), 6.80 (s, 2H), 2.53

(s, 6H), 2.47 (s, 6H); 13 C-NMR (75 MHz, CDCl3) δ 197.58, 156.57, 156.09, 146.09, 145.23, 131.83, 130.11, 130.05, 128.63, 127.78, 122.63, 118.07, 107.03, 106.52, 30.55, 21.81;

ESIMS +: m/z (%): 1392 (25) [2M+Na]+, 707 (100) [M+Na]+, 684 (20) [M]+; HRMS (ESI)

Crystals were obtained upon recrystallisation from a dichloromethane/methanol mixture For compound 3-61, a small yellow block, 0.50 x 0.36 x 0.14 mm, was used for X-ray crystallographic data collection at 223(2) K using Mo (Kα) radiation 22039 reflections were

collected and 7254 were unique (R int = 0.0477) No symmetry higher than monoclinic was observed and the centrosymmetric alternative, P21/c, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were refined anisotropically All H atoms were placed in idealized locations For C36H28O10S2, monoclinic, P21/c, a = 11.1434(9), b = 16.8307(13), c = 16.9033(13) Å, α = 90, β = 92.116(2),

γ = 90 °, V = 3168.1(4) Å3, Z = 4, Dx = 1.436 Mg/m3, R1 = 0.0678, wR2 = 0.1535 based on 2σ(I) data

mg, 1.18 mmol) was added to a stirring solution of phenol (5-26) (100 mg, 1.06 mmol) and anhydrous K2CO3 (225 mg, 1.63 mmol) in 5 mL of anhydrous DMF After 18 h, the reaction was quenched by addition of aqueous 1M HCl The aqueous layer was extracted three times with 10 mL of Et2O The combined organic layers were washed three times with 1M HCl, water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (9/1 hexane/EtOAc)

to afford compound 5-29 in 73% yield (135 mg, 0.775 mmol) as a colourless oil IR (NaCl):

νmax = 2916, 2846, 1597, 1489, 1450, 1234, 1026 cm-1; 1 H NMR (500 MHz, CDCl3) δ 7.28 (m, 2H), 6.94 (m, 3H), 5.98 (m, 1H), 5.89 (m, 1H), 4.81 (m, 1H), 2.15 (m, 1H), 2.04 (m, 1H), 1.91 (m, 3H), 1.65 (m, 1H); 13 C NMR (125 MHz, CDCl3) δ 157.85, 132.04, 129.45, 126.42, 120.61, 115.90, 70.82, 28.32, 25.11, 19.01

2-(Cyclohex-2-enyl)phenol ( 5-30 ) Highly viscous ether 5-29 (122 mg, 0.700 mmol) was transferred into a microwave oven vial (suitable for 0.2 to 0.5 mL) and flushed with argon gas before capping the vial The vial was placed inside a microwave oven and heated up to 190 °C After 1 hour, the reaction was completed and the reaction mixture was immediately purified by silica gel column chromatography (100% hexane to 9/1 hexane/EtOAc) to afford compound 5-30 in 98% yield

(119 mg, 0.683 mmol) as a colourless oil IR (NaCl): νmax = 3387, 2916, 2846, 1026 cm-1; 1 H

1H), 3.57 (m, 1H), 2.15 (m, 2H), 2.02 (m, 1H), 1.81 (m, 1H), 1.66 (m, 2H); 13 C NMR (125

MHz, CDCl3) δ 154.01, 130.85, 129.70, 129.58, 129.52, 127.52, 120.61, 116.14, 38.07, 29.95, 25.00, 21.43

mmol) was dissolved in 2 mL of anhydrous pyridine The colourless solution was cooled with an ice-water bath to 0 °C and freshly distilled acetyl chloride (55.0 mg, 0.692 mmol) was subsequently added by syringe After 30 minutes, the ice-water bath was removed and the reaction was stirred at room temperature After 6 hours, the reaction was quenched by the careful addition of 1M HCl The acidic aqueous layer was extracted three times with 10 mL DCM The combined organic layers were washed three times with 1M HCl, water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (100% hexane to 9/1 hexane/EtOAc) to afford compound 5-31 in 82% yield (101 mg, 0.467 mmol) as a colourless

oil IR (NaCl): νmax = 2916, 2854, 1759, 1658, 1373, 1188 cm-1; 1 H NMR (500 MHz, CDCl3)

δ 7.28 (m, 1 H), 7.21 (m, 2H), 7.01 (m, 1H), 5.90 (m, 1H), 5.62 (m, 1H), 3.52 (m, 1H), 2.31 (s, 3H), 2.08 (m, 2H), 1.95 (m, 1H), 1.73 (m, 1H), 1.59 (m, 2H); 13 C NMR (125 MHz,

CDCl3) δ 169.73, 148.47, 137.80, 129.45, 129.29, 128.60, 127.01, 126.06, 122.42, 35.97, 30.45, 24.89, 21.19, 20.98

mg, 2.202 mmol) was added portion wise to a stirring solution of acetyl protected phenol 5-31 (400 mg, 1.849 mmol) in 12 mL of chloroform After

4 h, the reaction was quenched by addition of a saturated solution of sodium bicarbonate The aqueous layer was extracted three times with 30 mL of chloroform The combined organic layers were washed two times with water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (100% hexane to 8/2 hexane/EtOAc) to afford compound 5-37 in 93% yield (0.401 g, 1.726 mmol) as a colourless

oil IR (NaCl): νmax = 2936, 2849, 1767, 1489, 1367, 1202, 1173, 1092, 1011, 916, 806, 752

3.13 (m, 1H), 2.34 (s, 3H), 2.18 (m, 1H), 1.79 (m, 2H), 1.44 (m, 2H), 1.26 (m, 1H); 13 C NMR

(125 MHz, CDCl3) δ 169.64, 169.52, 148.43, 135.75, 129.17, 129.03, 127.57, 127.47, 126.55, 126.26, 122.84, 122.09, 55.90, 55.50, 52.73, 51.90, 36.21, 36.11, 29.68, 28.03, 25.93, 24.62,

22.98, 21.58, 21.00, 20.96, 17.14 ) (Note: inseparable mixture of diastreomers)

meth-oxide (24 mg, 0.444 mmol) was added to a stirring solution of epmeth-oxide 5-37

(70 mg, 0.301 mmol) in 6 mL of absolute ethanol After 3 h, the reaction was quenched by addition of 1M HCl The acidic aqueous layer was extracted three times with 10 mL of Et2O The combined organic layers were washed two times with water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (2/1 hexane/EtOAc) to afford compound 5-39 in 87% yield (50 mg,

0.263 mmol) as a colourless oil IR (NaCl): νmax = 3385, 2937, 2864, 1491, 1460, 1261,

1061, 980, 947, 750 cm-1; 1 H NMR (500 MHz, CDCl3) δ 7.12 (m, 2 H), 6.89 (m, 1H), 6.84

0.390 mmol) was added to a stirring solution of secondary alcohol 5-39 (50

mg, 0.263 mmol) and sodium acetate (6 mg, 0.078 mmol) in 15 mL of DCM After 6 h, the reaction mixture was filtered through a plug of Celite and washed with two times 5 mL of DCM The filtrate was washed two times with water and brine, dried over

Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography ( 9/1 hexane/EtOAc) to afford ketone 5-41 in 65% yield (32 mg, 0.170

mmol) as a colourless oil IR (NaCl): νmax = 2957, 2926, 2855, 1732, 1597, 1462, 1261, 1134,

1034, 1015, 999, 799, 752 cm-1; 1 H NMR (500 MHz, CDCl3) δ 7.16 (m, 1H), 7.11 (m, 1H),

6.92 (m, 2H), 4.93 (d, J = 9.45 Hz, 1H), 4.08 (m, 1H), 2.52 (m, 1H), 2.43 (m, 1H), 2.16 (m,

1H), 1.96 (m, 2H), 1.80 (m, 1H); 13 C NMR (125 MHz, CDCl3) δ 208.09, 159.54, 128.67, 128.41, 123.29, 121.42, 110.22, 85.13, 44.73, 38.62, 26.53, 21.24

Crystals were obtained upon storage of the obtained oil in the fridge for several days For compound 5-41, a small colourless block, 0.56 x 0.25 x 0.14 mm, was used for X-ray crystallographic data collection at 100(2) K using Mo (Kα) radiation 12239 reflections were

collected and 4266 were unique (R int = 0.0309) No symmetry higher than triclinic was observed and the centrosymmetric alternative, Pī, was chosen based on the results of refinement Direct methods were used to solve the structure and all non-hydrogen atoms were refined anisotropically All H atoms were placed in idealized locations For C12H12O2, triclinic, Pī, a = 9.217(2), b = 9.311(2), c = 11.753(3) Å, α = 95.368(5), β = 103.158(4), γ =

68% yield (2.08 g, 8.95 mmol) as a colourless oil IR (NaCl): νmax = 3030, 2938, 1624, 1501,

1 hour, the reaction was terminated and the reaction mixture was immediately purified by silica gel column chromatography (4/1 hexane/EtOAc) The 1H NMR taken subsequently revealed a mixture of 2 regio-isomers which could be easily separated by a second silica gel

5-33

OH

O

HO

column chromatography (100% DCM) to afford the desired regio-isomer 5-33 in 13% yield

(92 mg, 0.40 mmol) as a colourless oil IR (NaCl): νmax = 3287, 2920, 1634, 1504, 1371,

1238, 1186, 1130, 1040, 955, 837 cm-1; 1 H NMR (500 MHz, CDCl3) δ 12.52 (s, 1 H), 7.46 (s, 1H), 6.36 (s, 1H), 6.21 (bs, 1H), 6.08 (m, 1H), 5.78 (m, 1H), 3.56 (m, 1H), 2.55 (s, 3H), 2.13 (m, 2H), 2.00 (m, 1H), 1.77 (m, 1H), 1.63 (m, 2H); 13 C NMR (125 MHz, CDCl3) δ 202.66, 163.43, 161.26, 132.00, 131.38, 129.18, 123.33, 114.06, 104.04, 36.87, 30.08, 26.24, 24.95

21.06; ESIMSˉ: m/z (%): 231 (100) [M–H]ˉ; HRMS (ESI) m/z: 233.1163 [calcd [M+H]+ of 233.1178 for C14H17O3]

5-28 (930 mg, 4.00 mmol) was dissolved in 5 mL of anhydrous pyridine The colourless solution was cooled with an ice-water bath to

0 °C and subsequently freshly distilled acetyl chloride (950 mg, 11.95 mmol) was added by syringe After 30 minutes, the ice-water bath was removed and the reaction was stirred at room temperature After 14 hours, the reaction was quenched by careful addition of 1M HCl The acidic aqueous layer was extracted three times with 30 mL DCM The combined organic layers were washed three times with 1M HCl, water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (5/1 hexane/EtOAc) to afford compound 5-32 in 99% yield (1.09 g, 3.97 mmol) as a colourless oil

1200, 1126, 1064, 1015, 937, 895, 818, 733 cm-1; 1 H NMR (500 MHz, CDCl3) δ 7.81 (d, J = 8.85 Hz, 1 H), 6.81 (dd, J = 2.55, 8.85 Hz, 1H), 6.61 (d, J = 2.55 Hz, 1 H), 5.99 (m, 1H), 8.82

(m, 1H), 4.83 (bs, 1H), 2.49 (s, 3H), 2.34 (s, 3H), 2.13 (m, 1H), 2.02 (m, 1H), 1,95 (m, 1H), 1.84 (m, 2H), 1.64 (m, 1H); 13 C NMR (125 MHz, CDCl3) δ 195.54, 169.37, 162.23, 151.40, 133.03, 132.52, 125.07, 122.56, 112.84, 110.54, 71.38, 28.89, 28.05, 24.92, 21.15, 18.73;

ESIMS +: m/z (%): 275 (100) [M+H]+, 297 (80) [M+Na]+; HRMS (ESI) m/z: 275.1272 [calcd

[M+H]+ of 275.1283 for C16H19O4]

5-35 was synthesized employing 2 different methods Method A:

Dihydroxybenzene 5-33 (80 mg, 0.344 mmol) was dissolved in 2 mL of anhydrous pyridine The colourless solution was cooled with an ice-water bath to 0 °C and subsequently freshly distilled acetyl chloride (90 mg, 1.132 mmol) was added by syringe After 30 minutes, the ice-water bath was removed and the reaction was stirred at room temperature After 11 hours, the reaction was quenched by the careful addition of 1M HCl The acidic aqueous layer was extracted three times with 10 mL DCM The combined organic layers were washed three times with 1M HCl, water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (4/1 hexane/EtOAc) to afford compound 5-35 in 82% yield (89 mg, 0.281 mmol) as a colourless

oil Method B: Ether 5-32 (1.09 g, 3.97 mmol) was dissolved in N,N-dimethylaniline (7 mL)

and transferred into a microwave oven vial (suitable for up to 20 mL) The reaction mixture was cooled to 0 °C and acetic anhydride (3.5 mL) was added carefully The vial was flushed with argon gas before capping the vial, subsequently placed inside a microwave oven and heated up to 190 °C After 2 hours, the progress of the reaction was checked Significant amounts of starting material were still seen and, therefore, the reaction was subjected for further 2 hours using the same conditions as previously Subsequently, the reaction mixture was carefully poured into 25 mL of cold 1M HCl The acidic aqueous layer was extracted three times with 20 mL DCM The combined organic layers were washed three times with 1M HCl, water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified

by silica gel column chromatography (4/1 hexane/EtOAc) to afford compound 5-35 in 42%

yield (530 mg, 1.675 mmol) as a colourless oil IR (NaCl): νmax = 3021, 2926, 1767, 1688,

C18H21O5]

4-acetyl-6-(7-oxabicyclo[4.1.0]heptan-2-yl)-1,3-phenylenediacetate

stirring solution of acetyl protected phenol 5-35 (510 mg, 1.612 mmol)

in 15 mL of chloroform After 6 h, the reaction was quenched by addition of a saturated solution of sodium bicarbonate The aqueous layer was extracted three times with 20 mL of chloroform The combined organic layers were washed two times with water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (2/1 hexane/EtOAc) to afford compound 5-38 in 91% yield (490 mg, 1.474

mmol) as a colourless oil IR (NaCl): νmax = 3493, 2938, 2862, 1759, 1682, 1493, 1368, 1196,

1126, 1045, 918, 735 cm-1; 1 H NMR (500 MHz, CDCl3) δ 8.11 (s, 1H, minor), 7.73 (s, 1H, major), 7.00 (s, 1H), 6.91 (s, 1H), 3.31-3.29 (m, 1H), 3.24-3.21 (m, 2H), 3.17-3.13 (m, 0.65H, minor), 3.10-3.09 (m, 1H, major), 2.57 (s, 3H, minor), 2.55 (s, 3H, major), 2.35 (s, 3H), 2.34 (s, 3H), 2.32 (s, 2H), 2.21-2.17 (m, 1H), 1.93-1.74 (m, 3H), 1.56-1.52 (m, 2H), 1.49-1.43 (m,

2H), 1.31-1.24 (m, 3H) (Note: inseparable 2:1-mixture of diastreomers); 13 C NMR (125

MHz, CDCl3) δ 196.85, 196.37, 169.29, 169.05, 168.97, 168.60, 168.46, 151.57, 151.24, 148.26, 148.07, 134.66, 133.94, 133.74, 133.67, 131.17, 131.01, 130.60, 130.20, 129.80, 128.68, 128.65, 128.24, 118.45, 117.93, 60.38, 55.53, 55.12, 52.71, 52.08, 36.05, 35.81, 29.73, 29.67, 29.16, 27.90, 26.08, 24.50, 22.82, 21.38, 21.14, 21.05, 21.01, 20.96, 20.92,

17.15, 14.17; EIMS +: m/z (%): 703 (82) [2M+K]+, 687 (100) [2M+Na]+, 355 (40) [M+Na]+;

[M+Na]+ of 355.1158 for C18H20O6Na]

1-(3,6-dihydroxy-5a,6,7,8,9,9a-hexahydrodibenzo[b,d]furan-2-yl)-

to a stirring solution of epoxide 5-38 (70 mg, 0.301 mmol) in 6 mL of absolute ethanol After 4 h, the reaction was quenched by addition of 1M HCl The acidic aqueous layer was extracted three times with 10 mL of Et2O The combined organic layers were washed two times with water, brine, dried over Na2SO4 and evaporated under vacuum The residue was purified by silica gel column chromatography (2/1 hexane/EtOAc) to afford compound 5-40 in 65% yield (34 mg, 0.137 mmol) as a colourless

oil IR (NaCl): νmax = 3408, 2934, 2864, 1633, 1472, 1404, 1369, 1331, 1258, 1169, 1126,

1034, 984, 903, 841 cm-1; 1 H NMR (500 MHz, CDCl3) δ 13.02 (s, 1H), 7.36 (d, J = 1.25 Hz,

1 H), 6.40 (s, 1H), 4.60 (m, 1H), 3.64 (m, 1H), 3.57 (m, 1H), 2.04 (m, 1H), 1.86 (m, 2H), 1.69 (m, 1H), 1.38 (m, 2H); 13 C NMR (125 MHz, CDCl3) δ 202.10, 165.93, 165.91, 124.62,

122.74, 113.88, 99.59, 90.45, 71.03, 39.62, 29.69, 29.65, 26.25, 24.95, 19.30 (Note:

inseparable mixture of diastreomers); EIMS +: m/z (%): 875 (100), 519 (44), 449 (74), 249

(66) [M+H]+; HRMS (EI) m/z: 249.1114 [calcd [M+H]+ of 249.1127 for C14H17O4]

Biological assays and procedures

Specimen collection and crude extract preparation

Fruiting bodies were collected from L sulphureus in parasitic growth on Eucalyptus

cladocalyx (specimen XRI2018, 1.21 kg and specimen XRI2022, 0.92 kg), saprobic growth

on E cladocalyx (specimen XRI2102, 0.85 kg), saprobic growth on Quercus dumosa (specimen XRI2011, 0.34 kg), parasitic growth on Quercus dumosa (specimen XRI2032, 0.92