反应详情

To a solution of 0.43 g (1.0 mmole) of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxypregna-4,6-dien-3-one in 10 ml of methylene chloride was added 3 ml of 0.5M-aqueous sodium hydrogen carbonate solution under stirring and cooling in an ice-water bath, followed by gradual addition of 0.34 g (2.0 mmoles) of m-chloroperbenzoic acid. The mixture was stirred at room temperature for 2 days. The reaction mixture thus obtained was subjected to phase separation and the aqueous layer was extracted twice with 10 ml portions of methylene chloride. The extract was combined with the organic layer obtained above and the mixture was washed successively with aqueous potassium iodide solution and aqueous sodium chloride solution, and dried over magnesium sulfate. The solvent was then distilled off under reduced pressure and the residue was purified by silica gel chromatography (eluent: ethyl acetate-hexane=1:10, v/v) to recover 0.35 g of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α;6α,7α-diepoxypregn-4-en-3-one (yield: 79%). The 1H-MNR and IR spectra of this product were in agreement with those of the 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α;6α,7α-diepoxypregn-4-en-3-one obtained in Example 7.

1. temperaturecooling in an ice-water bath
2. stirringThe mixture was stirred at room temperature for 2 days
3. customThe reaction mixture thus obtained
4. customwas subjected to phase separation
5. extractionthe aqueous layer was extracted twice with 10 ml portions of methylene chloride
6. customobtained above and the mixture
7. washwas washed successively with aqueous potassium iodide solution and aqueous sodium chloride solution
8. dry with materialdried over magnesium sulfate
9. distillationThe solvent was then distilled off under reduced pressure
10. customthe residue was purified by silica gel chromatography (eluent
11. customethyl acetate-hexane=1:10, v/v) to recover 0.35 g of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α