Pyridine → 7alpha-(N,N-dimethylcarbamoyloxy)-20-(5,5-dimethyl-1,3-dioxan-2-yl)-1alpha,2alpha-epoxypregn-5-en-3beta-yl acetate

Participants

Reaction Conditions

Reaction Steps

A mixture of 49.0 mg (0.1 mole) of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxy-7α-hydroxypregna-5-en-3β-yl acetate, 0.24 ml (3 mmoles) of pyridine, 0.5 mg (0.004 mmole) of 4-(dimethylamino)pyridine, 0.12 ml (1.3 mmoles) of N,N-dimethylcarbamoyl chloride and 10 ml of dry toluene was stirred at a temperature of 60° C. for 10 hours. The reaction mixture thus obtained was cooled to room temperature, diluted with 50 ml of methylene chloride, washed with water 3 times and finally washed with aqueous sodium chloride solution. The organic layer was dried over magnesium sulfate and the solvent was distilled off under reduced pressure. Finally the residue was purified by silica gel chromatography (eluent:ethyl acetate-hexane=1:10, v/v) to recover 37 mg of 7α-(N,N-dimethylcarbamoyloxy)-20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxypregn-5-en-3β-yl acetate (yield: 70%).

Provenance & Evidence