SYNTHESIS OF 16-METHYLENE PREDNISONE ACETATE

An alterative route for the synthesis of 16-methylene prednisone acetate (Ⅵ) is reported. Thus microbiological hydroxylation of 16α-, 17α-epoxide-16β-methyl-△⁴-pregne-3, 20-dione (I) with Rhizopus nigricans afforded the 11_α-hydroxyl compound Ⅱ, which was oxidizied to the 11-keto compound Ⅲ The cleavage of 16α-, 17α-epoxide afforded Ⅳ, which on introduction of C₂₁-acetoxy at and dehydrogenation at C₁ yielded the final product Ⅵ.