Hydride Transfers During Friedel Crafts Reactions of 5,5-Dimethyl-4,5-dihydrofuran-2(3H)-one

Abstract

5,5-Dimethyl-4,5-dihydrofuran-2(3H)-one (4,4-dimethylbutyrolactone) reacts with toluene and with p-xylene in the presence of anhydrous aluminium chloride to give 4-methylpentanoyl benzenes with one, two or three methyls on the benzene ring. Reduction of the side chain has taken place by hydride transfer from an aromatic methyl, the resulting benzylic carbocation going on to form diarylmethanes by reaction with solvent molecules.