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COMMUNICATIONS DOI: 10.1002/adsc.200700570 Organocatalytic Highly Enantioselective Conjugate Addition of Aldehydes to Alkylidine Malonates Gui-Ling Zhao,a,c Jan Vesely,a,c Junliang Sun,b,c Kirsten E. Christensen,b,c Charlotte Bonneau,b,c and Armando Crdovaa,c,* a Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden Fax: (+ 46)-8-154908; e-mail: acordova@organ.su.se b Structural Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden c Berzelii Center EXSELENT on Porous Materials, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden Received: December 4, 2007; Published online: March 17, 2008 Supporting information for this article is available on the WWW under http://asc.wiley-vch.de/home/. Abstract: The first highly enantioselective, direct scope of enamine catalysis to the use of aldehyde organocatalytic conjugate addition of unmodified donors and to this class of Michael acceptors is a aldehydes to alkylidinemalonates is presented. The useful and challenging objective. Based on this, and reaction gives access to b-formyl-substituted malo- the synthetic utility and biological importance of nates and highly functionalized lactones with up to chiral malonates and lactones,[1,13] we began the task 14:1 dr and generally 94 to 99% ee. of developing an organocatalytic asymmetric conju- gate addition of unmodified aldehydes to alkylidine- Keywords: aldehydes; alkylidenemalonates;