Abstract Aliphatic α-substituted perfluoroacyl fluorides are converted to hindered ketones in low to moderate yields on refluxing in acetonitrile with alkali metal fluorides. Other products identified in hydrolyzed reaction mixtures include perfluoroolefins and monohydroperfluoro compounds. A mechanism involving the formation of a carbanion intermediate is proposed. Evidence for the formation of carbanions has been obtained by carrying out the reaction in ...