Chemoenzymatic epoxidation of alkenes by dimethyl carbonate and hydrogen peroxide

[GRAPHICS] Monoperoxy carbonic acid methyl ester can be generated under neutral condit ions by lipase-catalyzed perhydrolysis of dimethyl carbonate with hydrogen peroxide. It can be used in situ for the selective and efficient epoxidatio n of olefins; the unstable coproduct carbonic acid monomethylester decompos es to carbon dioxide and methanol, Thus, an "acid-free" Prileshajev epoxida tion is realized, which is especially useful for the epoxidation of acid-se nsitive substrates such as beta-pinene.