Lead Tetraacetate Oxidation of Trimethylsilyl Enol Ethers: Synthesis of Aryl Substituted Phenacyl Acetates

Abstract

Standard methods for the preparation of phenacyl acetate include the acetolysis of both α-diazoacetophenone¹ and α-bromoace-tophenone², as well as the treatment of acetophenone with lead tetraacetate (LTA) in refluxing benzene^3. We should like to report that trimethylsilyl enol ethers, 1, react with LTA at room temperature in benzene to afford, after hydrolysis, excellent yields of aryl substituted phenacyl acetates, 2 (Equation 1).

In terms of both yield and mildness of reaction conditions the method is to be recommended over current literature procedures. The ready hydrolysis of 2 into α-hydroxyketones, 3, serves to further extend the synthetic potential of the method^4,5 (Equation 2). The data in Table 1 summarize the results of the oxidation reaction.