Highly efficient ruthenium-catalyzed Oppenauer-type oxidations of secondary alcohols to ketones have been developed. The catalytic system consists of [(PPh,),RuCl,] (1) and K,CO, or (2) in refluxing acetone. The catalytic reaction is of high efficiency and permits a cata1yst:substrate ratio of 1 : lo00 at 56°C. In some cases the initial turnover rate exceeds 1500 h-'. The reaction was [ (C4Ph4COHOCC4Ph4)(p-H)(CO)4R~z]

Oxidation of 5-unsaturated 3beta-hydroxy steroids 1 to the corresponding 4-en-3-one derivatives 2 can be performed efficiently by acetone at reflux in the presence of a catalytic system consisting of either (PPh(3))(3)RuCl(2) (3) and K(2)CO(3) or [(C(4)Ph(4)COHOCC(4)Ph(4))(&mgr;-H)][(CO)(4)Ru(2)] (4). The reaction proceeds via a ruthenium-catalyzed dehydrogenation of 1 and subsequent hydrogen transfer to acetone with concomitant double bond migration.

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