Efficient catalytic methods for the Baeyer–Villiger oxidation and epoxidation with hydrogen peroxide

We have found that the Baeyer–Villiger oxidation of cyclohexanone with hydrogen peroxide in 1,1,1,3,3,3-hexafluoro-2-propanol as solvent is catalyzed by Brønsted acids: in the presence of 1 mol% of p-TsOH, transformation to ε-caprolactone occurs rapidly and under mild conditions. Epoxidation of 1-octene can be performed just as efficiently in the presence of 1 mol% of benzenearsonic acid. Since Brønsted acids do not effect epoxidation under these conditions, the formation of perarsonic acid appears to be the crucial feature of the latter catalyst.