Development of the juliá asymmetric epoxidation reaction. Part 1. Application of the oxidation to enones other than chalcones
Abstract
Asymmetric epoxidation of a variety of enones 3, 6, 8, 10, 12, 14, 16, 18, 21, 22, 26, 28–30 and 36 gives the corresponding oxiranes in good to excellent yield and optical purity. The oxidation medium consists of basic peroxide or sodium perborate or sodium percarbonate or tert-butylhydroperoxide and the preferred catalyst is polyleucine, conveniently prepared from the N-carboxyanhydride using 1,3-diaminopropane.