Stereoselective and regioselective synthesis of azepane and azepine derivatives via piperidine ring expansion

摘要

Diastereomerically pure azepane derivatives 5, 13 were prepared by piperidine ring expansion with exclusivenstereoselectivity and regioselectivity and in excellent yield. The structure and stereochemistry of 5 were confirmednvia X-ray crystallographic analysis. The ring expansion strategy was applied to the construction of an azepinenbackbone 22 of a potential biologically active compound. The regiochemistry and stereochemistry of thenpiperidine ring expansion process were investigated by semiempirical molecular orbital calculations.