Chiral Ligand-Controlled Asymmetric Conjugate Addition of. ALPHA.-Trimethylsilanylacetate to Acyclic and Cyclic Enones

M Iguchi, H Doi, S Hata, K Tomioka

Index: Iguchi, Mayu; Doi, Hirohisa; Hata, Seiji; Tomioka, Kiyoshi Chemical and Pharmaceutical Bulletin, 2004 , vol. 52, # 1 p. 125 - 129

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Citation Number: 8

Abstract

The reaction of lithium ester enolate with enones provides a challenge for chemoselectivity, that is, discrimination between a conjugate addition and a 1, 2-addition. Asymmetric conjugate addition of a lithium enolate of α-trimethylsilanylacetate to acyclic and cyclic α, β- unsaturated ketones was mediated by an external chiral ligand to give the corresponding 1, 4-adducts in good enantioselectivity of 74% and good chemoselectivity.