Reaction Steps
A solution of (6-(6-(hydroxymethyl)-2,3,4-trimethoxyphenyl)benzo[d][1,3]dioxol-5-yl)methanol (170 mg, 0.48 mmol) in THF (2 mL), 2M HCl (2 mL) and concentrated hydrochloric acid (1 mL) was stirred under reflux for 3 hours. Water (15 mL) and ethyl acetate (15 mL) were added to the reaction, the layers were separated and the aqueous layer was extracted with ethyl acetate (2×10 mL). The extracts were combined, dried over Na2SO4, filtered and concentrated in vacuo. Flash chromatography of the residue over silica gel (20 g), eluting with hexane-ethyl acetate (4:1), followed by crystallisation (ethyl acetate) yielded the title compound as large clear crystals (103 mg, 64%); m.p. 154-156° C.; Elemental Analysis Found: C, 65.3; H, 5.5 (C18H18O6 requires C, 65.45; H, 5.49%); NMR Spectrum δH (300 MHz, CDCl3) 7.21 (1H, s, 12-H), 6.98 (1H, s, 8-H), 6.96 (1H, s, 4-H), 6.75 (1H, s, 4-H), 6.04 (2H, d, J 4.8 Hz, 10-H2), 4.40 (2H, d, J 11.2 Hz, 5-H2), 4.04 (1H, d, J 10.8 Hz, 7-HA), 4.01 (1H, d, J 10.8 Hz, 7-HB), 3.96 (3H, s, OCH3), 3.91 (3H, s, OCH3), 3.71 (3H, s, OCH3); NMR Spectrum δC (75 MHz, CDCl3) 56.3, 61.2, 61.5, 67.6, 67.8, 101.6, 109.0, 109.9, 110.2, 126.8, 129.5, 131.3, 131.7, 143.0, 147.3, 147.7, 150.8, 153.3; νmax/cm−1 (thin film) 2967, 2932, 2866, 1600, 1484, 1460, 1414, 1324, 1239, 1146, 1107, 1045; m/z (ES) 301 (MH+—CH2O, 100%); Rf (hexane-ethyl acetate 4:1) 0.28.
