Diisopropylamine → HCID 54358533, compound

Participants

Reaction Conditions

Reaction Steps

In 2 ml of tetrahydrofuran was dissolved 45 mg of 20-methyl-1α,3β-diacetoxy-21-phenylsulfonylpregna-5,7-diene and the solution was cooled in a dry ice-acetone bath under argon atmosphere. A 0.35-ml portion of a lithium diisopropylamide solution prepared from 2 ml of a 1.5N hexane solution of butyllithium and 0.5 ml of diisopropylamine in 10 ml of tetrahydrofuran was added and the resulting mixture was stirred at -30° C. for 30 minutes. The mixture was again cooled in a dry ice-acetone bath and then a solution of 150 mg of 1,2-epoxy-3-methylbutane in 1 ml of tetrahydrofuran was added, and the resulting mixture was stirred at -30° C. to -20° C. for 6 hours. A saturated aqueous solution of ammonium chloride was added to the reaction mixture and the mixture was allowed to warm to ambient temperature. Diethyl ether was then added to the reaction mixture, the organic layer was separated, and the aqueous layer was extracted with diethyl ether. The organic layer was combined, washed in sequence with an aqueous solution of sodium hydrogen carbonate and an aqueous solution of sodium chloride, then dried over sodium sulfate and concentrated. The residue was purified by silica gel thin layer chromatography to give 21 mg of 1α,3β-diacetoxy-22-phenylsulfonylcholesta-5,7-dien-24-ol.

Provenance & Evidence