Diastereoselective Alkylations of Oxazolidinone Glycolates:  A Useful Extension of the Evans Asymmetric Alkylation

The diastereoselective alkylation of glycolate oxazolidinones has been demonstrated as a method for the enantioselective preparation of α-alkoxy carboxylic acid derivatives and selectively protected 1,2-diols. Various protecting groups on the glycolate hydroxyl and multiple substitution patterns on allylic iodides are tolerated in the alkylation. Yields for the alkylations are typically 70−85% with diastereoselectivities of >98:2.