Synthesis 2011(12): 1887-1895  
DOI: 10.1055/s-0030-1260469
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Organocatalytic Domino Double Michael Reaction of Ethyl (E)-7-Oxohept-2-enoate and α,β-Unsaturated Aldehydes: Efficient Asymmetric Synthesis of Cyclohexanes with Four Contiguous Stereocenters

Bor-Cherng Hong*a, Amit A. Sadania, Roshan Y. Nimjea, Nitin S. Dangea, Gene-Hsiang Leeb
a Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi, 621, Taiwan, R.O.C.
Fax: +886(5)2721040; e-Mail: chebch@ccu.edu.tw;
b Instrumentation Center, National Taiwan University, Taipei, 106, Taiwan, R.O.C.
Further Information

Publication History

Received 14 March 2011
Publication Date:
16 May 2011 (online)

Abstract

Organocatalytic domino double Michael reactions of ethyl (E)-7-oxohept-2-enoate and α,β-unsaturated aldehydes provided ethyl 2-(2,4-diformyl-3-phenylcyclohexyl)acetate with excellent diastereoselectivities (>20:1 dr) and enantioselectivities (>99% ee). The adducts were further transformed to octahydro-3H-2-benzopyran-3-ones, octahydroisoquinolin-3(2H)-ones, and decahydro-5H-oxazolo[2,3-a]isoquinolin-5-ones.

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The reaction with 1 equiv of dl-Ser-OMeHCl for 8 h resulted in ˜50% conversion of 3a.

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CCDC-815738 contains the supplementary crystallographic data for (-)-3e, radiation type: CuKα. CCDC-815739 contains the supplementary crystallographic data for (-)-3e, radiation type: MoKα. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.