A [3+3] cyclization strategy for asymmetric synthesis of alkyl substituted piperidine-2-ones using 1,2-cyclic sulfamidates: a formal synthesis of (S)-coniine from L-norvaline

Karanfil, A; Balta, B; Eskici, M

A [3+3] cyclization strategy for asymmetric synthesis of alkyl substituted piperidine-2-ones using 1,2-cyclic sulfamidates: a formal synthesis of (S)-coniine from L-norvaline

Authors

Karanfil, A

Balta, B

Eskici, M

Publisher

PERGAMON-ELSEVIER SCIENCE LTD

Abstract

Regioselective ring-opening reactions of a set of representative 1,2-cyclic sulfamidates with lithium triethylorthopropiolate proceeded efficiently to deliver the corresponding delta-amino-alpha,beta-unsaturated esters after acidic hydrolysis. Hydrogenation of the unsaturated esters and subsequent thermal cyclization afforded the related alkyl substituted piperidine-2-ones. This approach represents a novel [3+3] cyclization strategy for the asymmetric synthesis of alkyl substituted piperidin-2-ones. Efficiency of the cyclization process is illustrated by a formal asymmetric synthesis of (S)-coniine from L-norvaline. (c) 2012 Elsevier Ltd. All rights reserved.