Trifluoroacetic anhydride → HCID 13477374, compound

Participants

Reaction Steps

A solution of 3.3 g of 17α-hydroxy-16β-methyl-6-methylene-4,9(11)-pregnadiene-3,20-dione in 40 ml of glacial acetic acid is cooled to 0° C. and stirred, after adding 15 ml of trifluoroacetic acid anhydride dropwise, for one hour at room temperature. After precipitation into ice water-sodium chloride, the mixture is filtered off and worked up as usual. The crude product is purified on 450 g of silica gel with a hexane-ethyl acetate gradient (0-50% ethyl acetate), thus obtaining 2.3 g of 17α-acetoxy-16β-methyl-6-methylene-4,9(11)-pregnadiene-3,20-dione, mp 197°-198° C.

Provenance & Evidence