An efficient ketone-catalyzed epoxidation using hydrogen peroxide as oxidant.

Epoxides are very important building blocks in organic synthesis.1 Dioxiranes, either isolated or generated in situ, have been shown to be extremely versatile epoxidation reagents.2-6 In nearly every case, the generation of dioxiranes uses potassium peroxomonosulfate (KHSO5) as oxidant (Scheme 1).7,8 During our recent study on asymmetric epoxidation using the fructose-derived ketone (1), we found that hydrogen peroxide (H2O2) could be used as primary oxidant in combination with acetonitrile (eq 1).6l High yields and ee’s were obtained for a number of