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Synfacts 2007(10): 1070-1070  
DOI: 10.1055/s-2007-963853
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Stereoselective Synthesis of Highly Substituted Cyclopropanes

Contributor(s): Mark Lautens, Frédéric Ménard
J. M. Concellón*, H. Rodríguez-Solla, C. Méjica, E. G. Blanco
Universidad de Oviedo, Spain
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Publication History

Publication Date:
07 November 2007 (online)

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Significance

Cyclopropanation of highly substituted and Z-conjugated alkenes remains a significant challenge.This report describes a solution to the problem. The method is stereoselective, and the dr in the products 2a-f reflects the Z/E ratio of the starting alkene. Reaction of morpholine amides 3 with organolithiums afforded cyclo­propylketones 4 without loss of diastereoselecti­vity. The reaction is noteworthy for its simplicity, and for its chemoselectivity (only the proximal alkene reacted to 2b).