Control of stereochemistry with phosphine oxides: asymmetric synthesis of 4-alkenyloxazolidin-2-ones with 1,4-related stereogenic centres across a double bond

Abstract

Treatment of optically active epoxyurethanes with four contiguous stereogenic centres [derived from a kinetic resolution during Sharpless epoxidation of diphenylphosphinoyl (Ph₂PO) allylic alcohols] with base leads to sequential regioselective intramolecular nucleophilic attack (on the epoxide) and Horner–Wittig elimination to give single geometrical isomers of alkenyl oxazolidinones. Any stereoisomer of 4-alkenyloxazolidin-2-ones containing 1,4-related stereogenic centres spanning a double bond of either geometry can be produced with control over geometrical (E,Z), relative (syn,anti) and absolute (R,S) stereochemistry.