Process for the preparation of alpha-tocopherol or alpha-tocopheryl acetate by reacting trimethylhydroquinone and phytol or isophytol and recycling the zinc halogenide condensation catalyst

摘要

Preparation of alpha -tocopherol or alpha -tocopheryl acetate comprises reaction of 2,3,5-trimethylhydroquinone (TMH) with phytol or isophytol (IP) in the presence of a zinc halide condensation catalyst and a proton donor, optionally with a final esterification step using acetic anhydride. The reaction involves: (A) a water immiscible or poorly water-miscible non-polar solvent; and (B) 1-4 mole water per mole zinc halide.