A new method for the synthesis of c-caprolactone based on the Baeyer-Villiger oxidation of cyclohexanone was developed. In the proposed reaction, potassium peroxomonosulphate was used as an oxidising agent under phase transfer catalysis conditions. The effects of the reaction parameters, including the type of phase transfer catalyst, the concentration of the oxidising agent, the type of organic solvent and temperature, were investigated. When dichloromethane was used as an organic solvent and an adequate amount of water was added to the reaction mixture, the highest yield and selectivity for epsilon-caprolactone were achieved at 40 degrees C. 2011 Elsevier B.V. All rights reserved.