Environmentally benign oxidation using a palladium catalyst system

A clean and environmentally benign process to convert benzylic and allylic alcohols into the corresponding carbonyl compounds using a catalytic amount of palladium on activated charcoal under an ethylene atmosphere is developed. The combination of Pd(OAc)2 and vinyl acetate is an excellent system. The efficient conversion is based on hydrogen transfer between allylic and benzylic alcohols and simple olefins such as ethylene and vinyl acetate. In the oxidation of D-glucal to the corresponding enone (1,5-anhydrohex-1-en-3-ulose), the palladium catalyst is proven to be reused without a decrease of catalytic activity. This extremely simple process is not only economically advantageous but it is also environmentally friendly in comparison to conventional methods using chromium or manganese salts.