The epoxidation of olefins (especially for electron-rich olefins) with para-toluenesulfonic peroxy acid generated in situ from the reaction of para-toluenesulfonyl fluoride with hydrogen peroxide in the presence of base was investigated. On treatment with para-toluenesulfonyl fluoride/hydrogen peroxide/sodium hydroxide system, sterically less hindered electron-rich olefins were epoxidized to give the corresponding epoxides in high yields, while the sterically hindered electron-rich olefins in medium yields. α,β-Unsaturated ketone was also epoxidized in a high yield by this system.

Key words: p-toluenesulfonic peracid, p-toluenesulfonyl fluoride, olefin, epoxidation