m-Chloroperbenzoic acid → 21-Chloro-9-fluoro-11beta,17-dihydroxy-16alpha-[(2-methyloxiranyl)methoxy]pregna-1,4-diene-3,20-dione

Participants

Reaction Steps

A solution of 3.0 g of 21-chloro-9-fluoro-11β,17-dihydroxy-16α-[ (2-methyl-2-propenyl)oxy]pregna-1,4-diene-3,20-dione in 100 ml of dichloromethane is stirred with 1.4 g of m-chloroperbenzoic acid for 210 minutes. The solution is washed with a mixture of 10% potassium carbonate solution and 10% sodium sulfite solution, dried, and evaporated in vacuo to give an oil which solidifies on standing. Recrystallization from acetone-hexane gives 1.94 g as a first crop, and 820 mg as a second crop. Recrystallization of 600 mg of crop 1 from acetone-hexane gives 460 mg of 21-chloro-9-fluoro-11β,17-dihydroxy-16α-[(2-methyloxiranyl)methoxy]pregna-1,4-diene-3,20-dione, melting point 193°-236°C.

Provenance & Evidence