DL-alpha-Tocopherol → Alpha-Tocopherol Acetate

Participants

Reaction Steps

2.279 of TMHQ, 0.368 g of metallic tin powder and 0.041 g of zinc chloride were suspended in 15 ml of trichlene in an atmosphere of nitrogen. A solution of 4.939 g of phytyl chloride in 10 ml of trichlene was dripped into said suspension over a period of 2.5 hours under agitation and reflux. The reaction mixture was subjected to reflux under agitation for another 2 hours to obtain a reaction mixture containing dl-α-tocopherol which was substantially achromatic. To the reaction mixture was added 13.0 ml of acetic anhydride and 0.219 g of γ-picoline and the mixture was subjected to reflux for 2.5 hours. The lower boiling fractions were distilled off from the reaction mixture under reduced pressure. The reaction mixture was extracted with n-hexane in an amount of 50 ml, and the extract was washed 4 times with an aqueous solution of 2% sodium hydrosulfite, dried with anhydrous magnesium sulfate and concentrated under reduced pressure to obtain 7.167 g of dl-α-tocopheryl acetate which was a substantially achromatic viscous liquid. The absorbance of this crude dl-α-tocopheryl acetate was measured: E415 mμ40%EtOH =0.041. Estimation of this crude dl-α-tocopheryl acetate by liquid chromatography with the use of n-nonane as the standard indicated that its purity was 93.8% and the yield was 95.0%.

Provenance & Evidence