反应详情

Compound 30 (20 mg, 0.05 mmol) was refluxed with 1 M solution of KOH in MeOH (10 mL) for 2 h. The solution was cooled, and the solvent was removed under reduced pressure. The remaining solid was dissolved in water (10 mL) and then acidified to pH 1-2 with 10% aqueous HCl solution. The precipitate was collected by filtration, washed with water, and dried. The product was purified by column chromatography on silica gel using CH2Cl2/MeOH (20:1 to 10:1, v/v) to give 31 (11 mg, 56%) as a pale yellow powder. mp 273-275° C.; 1H NMR (CDCl3) δ 8.54 (s, 1H, H4), 7.49 (d, 1H, H5, J=8.1 Hz), 7.20 (d, 1H, H6, J=8.1 Hz), 6.76-6.82 (m, 3H, H2′+H5′+H6′), 6.03 (AB, 2H, 3′,4′-OCH2O—, Δδ=11.1 Hz), 5.88 (AB, 2H, 7,8-OCH2O—, Δδ=7.2 Hz), 3.62 (s, 3H, OCH3); MS (FAB, positive) m/z 395 [M+H]+.

1. temperatureThe solution was cooled
2. customthe solvent was removed under reduced pressure
3. dissolutionThe remaining solid was dissolved in water (10 mL)
4. filtrationThe precipitate was collected by filtration
5. washwashed with water
6. customdried
7. customThe product was purified by column chromatography on silica gel