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Synfacts 2007(3): 0318-0318  
DOI: 10.1055/s-2007-968233
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart · New York

Asymmetric Domino Mukaiyama-Michael-Addition-Lactonization

Contributor(s): Benjamin List, Corinna Reisinger
T. Tozawa, H. Nagao, Y. Yamane, T. Mukaiyama*
The Kitasato Institute, Tokyo, Mitsubishi Pharma Corporation, Yokohama and Kitasato University, Tokyo, Japan
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Publication History

Publication Date:
20 February 2007 (online)

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Significance

Herein the authors report a catalytic protocol for the synthesis of 3,4-dihydropyran-2-ones 3 via an asymmetric domino Mukaiyama-Michael-addition-lactonization sequence. In the presence of the chiral catalyst 4, a bulky quaternary ammonium phenoxide derived from cinchonidine, various ketene acetals 2 as well as a broad range of α,β-unsaturated ketones 1 were employed in the reaction giving diversely substituted dihydropyranones in excellent yields with high ­diastereo- (dr up to >99:1) and good enantioselectivities (er up to 98.5:1.5).