Water → 3-Acetoxy-1alpha-methylandrosta-2,4-dien-17-one

Participants

Reaction Conditions

Reaction Steps

14.2 g (50 mmol) of androsta-1,4-diene-3,17-dione is dissolved in 100 ml of anhydrous dioxane under nitrogen atmosphere. 716 mg (5 mmol) of copper(I) bromide is added and the solution is heated to 25° C. Then 47 ml (55 mmol) of a 10% solution of trimethyl aluminum in toluene is added to the reaction so that the temperature does not rise above 35° C. Then it is stirred for 1.5 hours more at 35° C. 16.84 g (0.165 mol) of acetic anhydride is added at 35° C. and the reaction solution is stirred for 1 hour more at 30° C. For completion of the reaction it is then heated for 15 minutes to 60° C. After cooling of the solution to 20° C., 4 ml of water dissolved in 20 ml of dioxane is added to the reaction for the hydrolysis and the solution is stirred again for 15 minutes. The inorganic solid is suctioned off on diatomaceous earth and the solid is washed again with 50 ml of dioxane. After concentration by evaporation of the solution on a rotary evaporator, 18 g of crude product is obtained, that is chromatographed on silica gel with hexane and an increasing part of ethyl acetate as eluent. After concentration by evaporation of the fractions, 11.4 g of 3-acetoxy-1α-methyl-androsta-2,4-dien-17-one (70% of theory) is obtained as viscous material that can be recrystallized from diisopropylether.

Provenance & Evidence