Barium manganate in microwave-assisted oxidation reactions: synthesis of lactones by oxidative cyclization of diols

Microwave irradiation of a range of diols at 150 °C in acetonitrile in the presence of three equivalents of barium manganate facilitates a novel tandem oxidation/heterocyclocondensation to give the corresponding lactone, including both small and medium ring lactones, in only one hour and in high yield without the need for chromatographic purification.