Hydrochloric Acid → alpha-Tocopherol

Participants

Reaction Steps

To a mixture consisting of 69.9 g (0.460 mol) of 2,3,5-trimethylhydroquinone, 52.5 g (0.386 mol) of zinc chloride, 150 ml of diethyl carbonate and 7.5 g of concentrated hydrochloric acid, 138.3 g (0.459 mol) of isophytol (purity: 98.3%) were added dropwise under stirring at 30°-40° C. over 3 hours. At the same temperature, the reaction mixture was stirred for additional 2 hours. After the reaction mixture was washed with 30 ml of water, the solvent was distilled off. Toluene (300 ml ) was added to the residue to dissolve the same. The resulting solution was washed successively with water, alkaline water and a saturated aqueous solution of NaCl, dried over magnesium sulfate and then concentrated under reduced pressure, whereby 201.2 g of the title compound were obtained as a brown oil (yield: 99.2%, GLC purity: 97.5%).

Provenance & Evidence