 In 2006, about 20% of acetic acid was used for TPA production.Acetic acid is often used as a solvent for reactions involving carbocations, such as Friedel-Crafts alkylation.For example, one stage in the commercial manufacture of synthetic camphor involves a Wagner-Meerwein rearrangement of camphene to isobornyl acetate; here acetic acid acts both as a solvent and as a nucleophile to trap the rearranged carbocation.