反应详情

In 200 ml of ethanol was dissolved 13.0 g of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxypregna-4,6-dien-3-one, followed by addition of 1.0 g of sodium borohydride under ice-cooling. The mixture was stirred at room temperature for 2 hours. The resulting reaction mixture was neutralized with diluted hydrochloric acid under ice-cooling, diluted with water and extracted with methylene chloride. The extract was washed with aqueous sodium chloride solution and dried over magnesium sulfate. The solvent was then distilled off under reduced pressure to recover 12.1 g of a crude product. Purification of this crude product by silica gel chromatography gave 10.6 g of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxypregna-4,6-dien-3α-ol (yield: 81%) having the following physical properties.

1. temperaturecooling
2. customThe resulting reaction mixture
3. temperaturecooling
4. extractionextracted with methylene chloride
5. washThe extract was washed with aqueous sodium chloride solution
6. dry with materialdried over magnesium sulfate
7. distillationThe solvent was then distilled off under reduced pressure
8. customto recover 12.1 g of a crude product
9. customPurification of this crude product by silica gel chromatography