Synthesis 2009(4): 687-690  
DOI: 10.1055/s-0028-1083284
PSP
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Enantioenriched α,α-Disubstituted Cyclopentenes Catalyzed by N-Heterocyclic Carbenes

Eric M. Phillips, Manabu Wadamoto, Karl A. Scheidt*
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
Fax: +1(847)4672184; e-Mail: scheidt@northwestern.edu;
Further Information

Publication History

Received 5 August 2008
Publication Date:
19 December 2008 (online)

Abstract

The desymmetrization of 1,3-diketones using N-heterocyclic carbenes results in the formation of highly enantioenriched cyclopentenes in good yield. The reaction proceeds through a catalytic intramolecular aldol reaction and subsequent β-lactone formation. The expulsion of carbon dioxide at mild reaction temperatures affords the cyclopentene products.