Efficient Synthesis of 21-Acetoxypregna-1,4,9(11),16-Tetraene-3,20-Dione, a Key Intermediate in the Synthesis of Highly Active Fluorinated Corticosteroids from 9-Hydroxyandrostenedione

摘要

An efficient synthesis of 21-acetoxypregna-1,4,9(11),16-tetraene-3,20-dione, a key intermediate in the synthesis of highly active fluorinated corticosteroids from phytosterols, was developed. The method consisted of an original sequence of chemical and microbiological reactions and could be used to synthesize betamethasone, sinaflan, triamcinolone, and other fluorinated corticoids.