反应详情

In 4 ml of methylene chloride was dissolved 208 mg of 17α-acetoxy-11β,21-dihydroxy-6α-methyl-1,4-pregnadiene-3,20-dione obtained according to the method as described in Example 6. To this solution was added 0.5 ml of pyridine, and the mixture was ice-cooled. To the mixture was added slowly a solution of 241 mg of valeryl chloride in 2 ml of methylene chloride, and the mixture was stirred for one hour. To this reaction liquid was added 60 ml of ethyl acetate, and the mixture was washed successively with 30 ml of water, 10 ml of a dilute aqueous solution of sodium carbonate, 30 ml of water, 5 ml of dilute hydrochloric acid and twice 30 ml of water and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated and the resultant residue was subjected to preparative thin layer chromatography (silica gel) for purification whereby 186 mg (yield: 87.4%) of the title compound was obtained as colorless needle crystals (recrystallized from ether-hexane). Shown below are physical properties and various analytical data of this compound.

1. customobtained
2. temperaturecooled
3. customTo this reaction liquid
4. washthe mixture was washed successively with 30 ml of water, 10 ml of a dilute aqueous solution of sodium carbonate, 30 ml of water, 5 ml of dilute hydrochloric acid and twice 30 ml of water
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationAfter filtration
7. concentrationthe filtrate was concentrated