反应详情

iv)—A solution of (3β,20S)-3-[(1-ethoxyethyl)oxy]pregn-5-en-20-ol acetate (66.1 g) in acetone (1330 ml) was treated with a 4 M aqueous solution of hydrochloric acid (13.2 ml). The reaction mixture was stirred for 45 min. and subsequently poured into a mixture of water (3 l) and a saturated aqueous solution of sodium hydrogen carbonate (500 ml). The resulting precipitate was collected by filtration and then dissolved in dichloromethane. The filtrate was extracted with ethyl acetate. The dichloromethane and ethyl acetate solutions were washed with a saturated aqueous solution of sodium hydrogen carbonate and with brine, dried over sodium sulfate, and concentrated under reduced pressure to give (3β,20S)-pregn-5-ene-3,20-diol 20-acetate (compound 5; 53.5 g), which was used in the following step without further purification.

1. filtrationThe resulting precipitate was collected by filtration
2. dissolutiondissolved in dichloromethane
3. extractionThe filtrate was extracted with ethyl acetate
4. washThe dichloromethane and ethyl acetate solutions were washed with a saturated aqueous solution of sodium hydrogen carbonate and with brine
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated under reduced pressure