反应详情

温度

-55 °C

A solution of 380 mg of 11β-chloro-7α-methyl-estr-4-ene-3,17-dione (F′) in 7.6 ml of tetrahydrofuran, 4.4 ml of ethanol and 1.15 ml of water was mixed at −55° C. in portions with 596 mg of sodium borohydride and stirred for 7 hours at −55° C. Then, the mixture was added to ice water, extracted three times with ethyl acetate, washed neutral, dried on sodium sulfate, concentrated by evaporation in a vacuum and chromatographed on silica gel with hexane/ethyl acetate. 130 mg of pure 11β-chloro-17β-hydroxy-7α-methyl-estr-4-en-3-one (I) was obtained ([α]D20=+136.9° (in chloroform), FD183.2° C.).

1. extractionextracted three times with ethyl acetate
2. washwashed neutral
3. customdried on sodium sulfate
4. concentrationconcentrated by evaporation in a vacuum
5. customchromatographed on silica gel with hexane/ethyl acetate