Synfacts 2007(10): 1074-1074  
DOI: 10.1055/s-2007-983859
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

1,3-syn-Polymethyl Array via Iterative Asymmetric 1,4-Additions

Contributor(s): Mark Lautens, Frédéric Ménard
B. ter Horst, B. L. Feringa*, A. J. Minnaard*
University of Groningen, The Netherlands
Further Information

Publication History

Publication Date:
07 November 2007 (online)

Significance

This report shows the impressive efficiency of the Cu-catalyzed 1,4-addition of Grignard reagents developed by Feringa and Minnaard. For the first time, an array of seven 1,3-syn-methyl groups (4) was synthesized in 8% yield after 19 steps (average of 87% per step). The poly­methyl array was further elaborated in five steps to obtain phthioceranic acid (7). Phthioceranic acid is contained in sulfolipid-I, which is a potential candidate for vaccines against M. tuberculosis.