Controlled Payne rearrangements of 2,3-epoxy alcohols in aprotic media: an enantioselective total synthesis of (+)-exo-brevicomin
Abstract
The catalysis of the isomerisation of primary cis-2,3-epoxy alcohols to threo-1,2-epoxy alcohols by lithium chloride in tetrahydrofuran solution is described; the more reactive terminal epoxides may be selectively trapped in situ by reaction with nucleophiles, and this methodology is used in an enantioselective synthesis of (+)-exo-brevicomin.