Chloroform → 17alpha-Acetoxy-1alpha-chloromethyl-6-methylene-4-pregnene-3,20-dione

Participants

Reaction Steps

A suspension of 9.0 g of sodium acetate in 270 ml of chloroform, 270 ml of formaldehyde dimethylacetal, and 35 ml of phosphorus oxychloride is stirred with 9.0 g of 17α-acetoxy-1α,2α-methylene-4-pregnene-3,20-dione for 5 hours at a bath temperature of 65° C. The reaction solution is neutralized with a saturated sodium carbonate solution and diluted with methylene chloride. The organic phase is separated and worked up as usual. The crude product is purified on 500 g of silica gel with a hexaneethyl acetate gradient (0-30% ethyl acetate), thus isolating 7.5 g of 17α-acetoxy-1α-chloromethyl-6-methylene-4-pregnene-3,20-dione, mp 190°-192° C.

Provenance & Evidence