We recently described the preparation of 3-nosyloxy-2-ketoesters 1 from a-ketoesters and some aspects of their use as precursors for the synthesis of 1,2,3_functionalized products.1 In contrast to the isomeric 2-nosyloxy-3-ketoesters 2 which are extraordinarily versatile intermediates,2 the synthetic utility of 1 is compromised by the extreme electrophilicity of the ketone carbonyl group which dominates the chemistry of 1. For example, the carbonyl group of 1 hydrates ...