Synthesis and Reactions of 3-(Nosyloxy)-2-keto Esters.

A series of 3-(nosyloxy)-2-keto esters 7a−j were prepared from the corresponding α-keto esters by conversion to the trimethylsilyl enol ether and reaction with p-nitrobenzenesulfonyl peroxide. Conversion of these materials to 1,2,3-trifunctionalized compounds is described, and comparison of their properties with isomeric 2-(nosyloxy)-3-keto esters is discussed.