The oxidation of propene has been studied with O-2 as the terminal oxidant using a carbon-supported gold palladium catalyst at 90 A degrees C. The reaction is carried out in acetonitrile as solvent in an autoclave. Propene oxidation is only observed in the presence of benzoyl peroxide acting as a radical initiator, but the presence of O-2 is essential to observe oxidation. The addition of aldehydes enhances the formation of the epoxide.