A Short and Flexible Synthetic Approach to the Naturally Occurring Racemic Neoclausenamide and Its Analogs

Abstract

A novel strategy was developed for a rapid access to the naturally occurring racemic neoclausenamide and its analogs, which featured a highly erythro-selective vinylogous Mukaiyama type reaction (dr=12:1) and a highly diastereoselective tandem conjugate addition-Davis oxidation of N-Boc-pyrrol-2(5H)-one 5 (dr=10:1). Remarkably, the skeleton of neoclausenamide, namely 8a, an analog of neoclausenamide, was built in just two steps with all the four stereogenic centers (relative stereochemistry) established correctly and in excellent diastereoselectivities.