Tetrapropylammonium perruthenate as a mild and efficient oxidant for sensitive steroidal alcohols

Tetrapropylammonium perruthenate N-methylmorpholine N-oxide oxidation of steroidal alcohols is described. The reagent combination is mild and gave good yields of the corresponding ketones. Although the oxidation can generate ketones from 3-, 11-, 15-, 17-, and 20-hydroxy steroids, the oxidation of homoallylic alcohols proceeds in low yields. Finally, we observed that the oxidation reagents will convert 17 alpha-hydroxy-20-keto steroids to 17-keto systems in excellent yield.