反应详情

3-Methoxyandrosta-3,5,9(11)-trien-17-one (IAa, 20 g) in THF (220 ml) was combined with dimethyloxylate (11.8 g) and sodium methoxide (25%, 18.4 ml) at 0° under nitrogen. After the reactants were combined, the ice was removed. After one hour, TLC shows the reaction has gone cleanly. Triethylamine (7.0 ml), acetic acid (1.0 ml), paraformaldehyde (3 g), and methanol (28 ml) were added and the mixture stirred overnight at 20°-25°. TLC showed the reaction had gone to completion. The reaction mixture was washed with phosphate buffer (121 ml) and water (202 ml). The mixture was extracted with methylene chloride (48 ml) and again with methylene chloride (40 ml). The methylene chloride extracts were combined and back-extracted with water (80 ml) and saline (10 ml). The organic mixture was concentrated under reduced presure to give the title compound.

1. customthe ice was removed
2. additionTriethylamine (7.0 ml), acetic acid (1.0 ml), paraformaldehyde (3 g), and methanol (28 ml) were added
3. washThe reaction mixture was washed with phosphate buffer (121 ml) and water (202 ml)
4. extractionThe mixture was extracted with methylene chloride (48 ml) and again with methylene chloride (40 ml)
5. extractionback-extracted with water (80 ml) and saline (10 ml)
6. concentrationThe organic mixture was concentrated under reduced presure