Organocatalytic Synthesis of Lactones by the Oxidation of Alkenoic Acids

Along the lines of modern sustainable oxidation, a green and mild organocatalytic synthetic procedure for the synthesis of hydroxylactones from alkenoic acids is described. The reaction includes the activation of H2O2 by an organocatalyst (2,2,2-trifluoromethylacetophenone), the oxidation of an olefinic group to the corresponding epoxide, and intramolecular lactonization to afford a variety of substituted gamma -or delta-lactones with multiple substitution patterns in good to high yields. The product can be obtained with high purity after simple extraction if the conversion is quantitative. Attempts to render the process asymmetric met with limited success.