O-Xylene → alpha-Tocopherol

Participants

Reaction Steps

Suspended in 100 ml of xylene were 20.0 g (131.6 mmol) of TMH and 16.3 g (26.3 mmol) of ytterbium trifluoromethanesulfonate, followed by heating under reflux for 5 minutes under an argon gas stream. After a solution of 43.0 g (145.0 mmol) of isophytol in 100 ml of xylene 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 1,000 ml of ethyl acetate were added. The resulting mixture was washed thrice with 2,000-ml portions of water and then with 2,000 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 35.5 g of the title compound were obtained in the form of a brown oil. (Yield: 59%, GLC purity: 91%)

Provenance & Evidence