反应详情

2α,3α-Epoxy-5α-pregnane-11,20-dione (207 mg.) in hot tetrahydrofuran (6 ml.) was treated with perchloric acid (60%, 0.05 ml.) in tetrahydrofuran (2 ml.) and water (2 ml.). The reaction mixture was concentrated to 5 ml., allowed to stand for 15 minutes and boiled for 30 minutes with the concurrent addition of water. The mixture was poured into ethyl acetate, and the aqueous layer was extracted with ethyl acetate. The combined organic extract was washed with water, dried over sodium sulphate and evaporated to a crystalline mass which was purified by preparative TLC to give the title compound (70 mg.) as colourless crystals, m.p. 194°-198°, [α]D + 103.5°.

1. concentrationThe reaction mixture was concentrated to 5 ml
2. additionboiled for 30 minutes with the concurrent addition of water
3. additionThe mixture was poured into ethyl acetate
4. extractionthe aqueous layer was extracted with ethyl acetate
5. extractionThe combined organic extract
6. washwas washed with water
7. dry with materialdried over sodium sulphate
8. customevaporated to a crystalline mass which
9. customwas purified by preparative TLC