Catalytic Asymmetric Synthesis of Apple Leafminer Pheromones

doi:10.1055/s-2005-865341

Synfacts 2005(0): 0001-0001
DOI: 10.1055/s-2005-865341

Synthesis of Natural Products and Drugs

Catalytic Asymmetric Synthesis of Apple Leafminer Pheromones

Contributor(s): Philip Kocienski

R. P. Van Summeren, S. J. W. Reijmer, B. L. Feringa*, A. J. Minaard
University of Groningen, The Netherlands
Catalytic Asymmetric Synthesis of Enantiopure Isoprenoid Building Blocks: Application in the Synthesis of Apple Laefminer Pheromones
Chem. Commun. 2005, 1387-1389

Abstract

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Key words

enantioselective catalytic 1,4-addition - desymmetrization - catalyst control - remote stereocontrol - organozinc reagents - phosphoramidite

Significance

Starting from cycloocta-2,7-dienone, all four diastereoisomeric 8-hydroxy-3,7-dimethyloctanoic acids were prepared in four steps (38% overall) and one of them (B) was transformed to pheromones C and D of the apple leafminer (Lyonetia prunifoliella) in a further four steps. A new method for the desymmetrization of cross-conjugated dienones is presented.

Comment

The key step in the synthesis is the powerful Cu-phosphoramidite-catalyzed enantioselective conjugate addition of dialkylzincs to enones. The method offers a general solution to the construction of carbon chains with alkyl groups in a 1,5-relationship. It complements the procedures of Noyori (Ru-catalyzed asymmetric hydrogenation of allylic alcohols) and Negishi (Zr-catalyzed enantioselective carboalumination) for the synthesis of isoprenoid chains. For reviews of enantioselective Cu-catalyzed conjugate addition see: A. Alexakis, C. Benhaim Eur. J. Org. Chem. 2002, 3221-3236; B. L. Feringa Acc. Chem. Res. 2000, 33, 346-353.

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