Simple and efficient stereocontrol of radical allylations of beta-hydroxy esters

Highly stereoselective radical allylations of non-protected beta-hydroxy esters have been achieved after formation of chelated aluminum alkoxides upon treatment with MeAlR(2). This approach combines very high selectivities, excellent reproductibility and simplicity of the manipulations. Interestingly, diethyl malate is allylated after treatment with 1.1 equiv. of MAD to the three (syn) isomer with almost complete diastereoselectivity (> 95% ds), this stereochemical outcome is opposite to the one observed in the well-known alkylation of the corresponding enolate. Copyright (C) 1996 Elsevier Science Ltd