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 Bronsted acids: in the presence of 1 mol% of p-TsOH, transformation to epsilon -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 Bronsted acids do not effect epoxidation under these conditions, the formation of perarsonic acid appears to be the crucial feature of the latter catalyst. (C) 2001 Elsevier Science Ltd. All rights reserved.