Ruthenium Tetroxide Oxidation of N-Alkyllactams

Abstract

Ruthenium tetroxide (Ru04) oxidation of N-alkyllactams proceeded regioselectively depending on the size of lactam ring, except for the seven-membered ring. Four- and eight-membered N-methyl-and N-ethyllactams were oxidized at the exocyclic a-carbon adjacent to nitrogen to produce the N-acyllactams and NH-lactams, while five- and six-membered lactams underwent endocyclic oxidation to yield the cyclic imides. Oxidation of seven-membered lactams yielded a mixture of products arising from both exocyclic and endocyclic oxidations. These regioselectivities were confirmed in the oxidation of substrates having a tertiary carbon at the oxidation position. © 1987, The Pharmaceutical Society of Japan. All rights reserved.