Perfluorinated bronsted 'superacids': Powerful catalysts for the preparation of vitamin E

The key-step in the industrial synthesis of (all-rac)-alpha-tocopherol (synthetic vitamin E) is the condensation reaction of trimethylhydroquinone with the C-20 building block isophytol. For this Friedel-Crafts-type reaction, perfluorinated NH- and CH-acidic compounds (perfluoroalkyl(aryl)sulfonyl imides and methides) have been applied as excellent catalysts, preferably in biphasic solvent systems.