Water → alpha-Tocopherol

Participants

Reaction Steps

Isophytol (98%, 25.5 g.) was added, dropwise, over three hours to a mixture of trimethylhydroquinone (14.5 g.), trifluoroacetic acid (65 ml.) and water (10 ml.). The product was diluted with hexane (200 ml.), washed with methanol-water (1:1, v:v)(3×100 ml.) and saturated aqueous sodium bicarbonate solution (100 ml.). A 1% by weight solution of potassium hydroxide in methanol (100 ml.) was added and the mixture was stirred at room temperature for 30 minutes. Then 2N aqueous hydrochloric acid (100 ml.) was added, the organic phase was separated, washed with saturated aqueous sodium bicarbonate solution (100 ml.) and methanol-water (1:1, v:v) (100 ml.). The hexane was removed by concentrating on a rotary evaporator and the resulting oil was flashdistilled to give α-tocopherol (29.6 g.; bp 220° C./0.1 mm.). Purity by area % glc was 100%.

Provenance & Evidence