The Acid-catalyzed Isomerization of an α-Ketoester into β-Ketoesters and the Unusual Fragmentation of an α-Ketoester. Preliminary communication

The first example of an acid‐catalyzed isomerization of an α‐ketoester into β‐ketoesters is described. Ethyl 2‐keto‐3,3‐diphenylbutyrate rearranged in fluorosulfonic acid at 0° into ethyl 2‐benzoyl‐2‐phenylpropionate and ethyl 2,2‐diphenylacetoacetate. In contrast, fragmentation of ethyl 3,3‐diphenylpyruvate to benzophenone occurred in the same conditions.