反应详情

Trimethylsilyl iodide (5.12 ml, 7.20 g, 36.0 mmol) is added dropwise to a solution of 17α,21-dihydroxypregna-1,4-diene-3,11,20-trione (3.23 g) in freshly distilled acetonitrile. After 30 min, sodium sulfite solution (5%, 150 ml) is added to the reaction mixture. The mixture is partitioned with chloroform (400 ml). The phases are separated, and the aqueous phases is extracted twice with chloroform. The organic layers are combined, washed with sodium bicarbonate (5%), saline, dried over sodium sulfate and concentrated. The concentrate is flash chromatographed eluting with ethyl acetate/hexane (2.3/1). The appropriate fractions are pooled to give 21-hydroxypregna-1,4-diene-3,11,20-trione as an oil and 17-epi-21-hydroxypregna-1,4-diene-3,11,20-trione as a solid, mp 203-206°.

1. customThe mixture is partitioned with chloroform (400 ml)
2. customThe phases are separated
3. extractionthe aqueous phases is extracted twice with chloroform
4. washwashed with sodium bicarbonate (5%), saline
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated
7. customchromatographed
8. washeluting with ethyl acetate/hexane (2.3/1)