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Full Paper
SN2′ Reactions between Lithiated Carbon Nucleophiles and Silylated Vinyloxiranes – Effects of Salts and Solvents on the Stereocontrol
Article first published online: 15 NOV 2005
DOI: 10.1002/ejoc.200500666
Copyright © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Additional Information
How to Cite
Marié, J.-C., Courillon, C. and Malacria, M. (2006), SN2′ Reactions between Lithiated Carbon Nucleophiles and Silylated Vinyloxiranes – Effects of Salts and Solvents on the Stereocontrol. Eur. J. Org. Chem., 2006: 463–470. doi: 10.1002/ejoc.200500666
Publication History
- Issue published online: 2 JAN 2006
- Article first published online: 15 NOV 2005
- Manuscript Received: 1 SEP 2005
- Abstract
- Article
- References
- Cited By
Keywords:
- Alcohols;
- Allylic compounds;
- Lithiation;
- Nucleophilic substitution;
- Oxygen heterocycles;
- Silicon
Abstract
(α,β-Epoxy-γ,δ-alkenyl)-tert-butyldimethylsilanes 1 display, a priori, three electrophilic centres and two acidic protons. Depending on the configurations of their oxirane rings, the title compounds react towards lithiated bases either through metallation or SN2′ reactions. In this paper we demonstrate that the trans-2-(tert-butyldimethylsilyl)-3-vinyloxiran 1a reacts regioselectively with primary, secondary and tertiary butyllithium in SN2′ fashion, which allows the formation of α-silylated allylic alcohols with diastereomeric ratios of over 7 to 1 in favour of the Z olefins. A study of the effect of temperature, time, addition of salt and polarity of the solvent on the diastereoselectivity of the reaction is described and the results are interpreted in terms of different mechanistic models. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)