Stereoselective oxidation of fusidic acid derivatives by the Corey oxidation procedure

Abstract

The Corey oxidation procedure (treatment with N-chlorosuccinimide–dimethyl sulphide complexes, then triethylamine) was applied to a series of fusidic acid derivatives. Stereoselective oxidation of the C-3 hydroxy-group can be accomplished. The reagent is highly sensitive to steric and electronic effects; for example successful oxidation of the second hydroxy-group at C-11 is dependent on the nature of the 16-substituent. Unexpectedly, the 16β-hydroxy-substrate (3) is quantitatively lactonised under these conditions. The reactivity of the 16-hydroxy-groups is discussed.