Sharpless Asymmetric Epoxidation

In 1980, K.B. Sharpless and T. Katsuki discovered that the combination of titanium (IV) tetraisopropoxide, optically active diethyl tartrate, and tert-butyl hydroperoxide caused a wide variety of allylic alcohols to epoxidize in high yields. The titanium(IV) alkoxide-catalyzed epoxidation of prochiral and chiral allylic alcohols, in the presence of a chiral tartrate ester and an alkyl hydroperoxide to provide enantiopure 2,3-epoxy alcohols, is now known as the Sharpless asymmetric epoxidation (SAE).

Only allylic alcohols are good substrates for this method, as the presence of a hydroxyl group is essential. The addition of catalytic amounts of molecular sieves allows for the use of only catalytic amounts of the titanium-tartrate complex; without the molecular sieves, a full equivalent of the complex is required.