Asymmetric epoxidation of unfunctionalized alkenes by dioxirane intermediates generated from potassium peroxomonosulphate and chiral ketones

Chiral dioxirane intermediates, which are formed in the reaction of potassium peroxomonosulphate with chiral ketones, allow the epoxidation of simple pro-chiral olefins to the corresponding epoxides to be carried out with enantiomeric excesses in the range 9–12.5%.