Toluene → alpha-Tocopherol

Participants

Reaction Steps

Suspended in 20 ml of ethyl acetate were 10.0 g (65.8 mmol) of trimethylhydroquinone (TMH) and 0.32 g (0.658 mmol) of scandium trifluoromethanesulfonate, followed by heating under reflux for 10 minutes under an argon gas stream. After a solution of 20.3 g (68.4 mmol) of isophytol in 20 ml of ethyl acetate was added dropwise over 30 minutes under heating and reflux, TMH and isophytol were reacted for 3 hours. The reaction mixture was cooled, to which 100 ml of toluene were added. The resulting mixture was washed twice with 200-ml portions of water and then concentrated under reduced pressure. The residue was added with 100 ml of toluene and 100 ml of 2-butanone. The organic layer was washed twice with 200-ml portions of a 1N aqueous solution of sodium hydroxide and then with 200 ml of a saturated aqueous solution of sodium chloride. The organic layer was then dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column (eluent: n-hexane-diethyl ether system), whereby 28.1 g of the title compound were obtained in the form of a brown oil. (Yield: 99%, GLC purity: 95%)

Provenance & Evidence