Synlett 2006(3): 0369-0374  
DOI: 10.1055/s-2006-926259
LETTER
© Georg Thieme Verlag Stuttgart · New York

Michael-Induced Ring Closure to 2-Azidocyclopropane-1,1-dicarboxylates and their Staudinger Reduction to 5-Alkoxy-3-(alkoxycarbonyl)pyrrolidin-2-ones

Sven Mangelinckx, Norbert De Kimpe*
Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
Fax: +32(9)2646243; e-Mail: norbert.dekimpe@UGent.be;
Weitere Informationen

Publikationsverlauf

Received 8 November 2005
Publikationsdatum:
06. Februar 2006 (online)

Zoom Image

Abstract

An easy and short synthesis of new β-azidocyclo­propanedicarboxylates, a rather unexplored class of conformationally constrained N-protected β-aminocyclopropanecarboxylic acid derivatives, is described. Michael-induced ring closure (MIRC) of sodium azide to 2-bromoalkylidenemalonates in alcoholic solvents leads to 3,3-dialkyl-2-azidocyclopropane-1,1-dicarboxylates, whereas other polar solvents give increasing amounts of competitive 2-azidoalkylidenemalonates. The reactivity of the azidocyclopropanes was investigated under reducing conditions, giving an easy access to diastereomeric mixtures of 5-alkoxy-3-(alkoxy­carbonyl)pyrrolidin-2-ones.