Regiospecificity in the Alkylation of Ester Enolates: Synthesis of Sterically Hindered Diarylketene Acetals

Article abstract of DOI:10.1021/jo00386a046

The alkylation of the enolates of methyl bis(pentamethylphenyl)acetate and of isopropyl bis(pentachlorophenyl)acetate occurs exclusively on oxygen to yield the diarylketene acetals; the extreme steric hindrance of these groups is also responsible for the stability of these ketene acetals in acid.