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DOI: 10.1039/A807863G (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 1, 1999, 155-162

The effects of different ester and ketal protecting groups on the reactivity and selectivity of tartrate-derived silylketene acetals

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Varinder K. Aggarwal, Susannah J. Masters, Harry Adams, Sharon E. Spey, George R. Brown and Alan J. Foubister

Abstract

The reaction of tartrate-derived silylketene acetals and benzaldehyde has been investigated and the yields and diastereoselectivities have been found to be dependent upon the nature of the tartrate ester. Utilising the di-tert-butyl tartrate derivatives, high yields were achieved using a variety of aldehyde substrates. The reactions all proceeded with excellent levels of stereoselectivity ([greater than or equal, slant] 82∶18); the sense of induction being dependent upon the choice of Lewis acid. BF3·OEt2 and TiCl3(OiPr) furnished complementary products in several cases and a model has been proposed to account for this observation.

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