Water → (S)-3-(Hexadecyloxy)propane-1,2-diol

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Reaction Steps

40 grams of (R)-(−)-2,2-dimethyl-1,3-dioxolane-4-methanol, 80 grams of powdered potassium hydroxide and 100 grams of hexadecyl bromide were stirred in 350 ml benzene and refluxed for 7 hours, while removing the water formed by azeotropic distillation. The volume of the solvent was gradually reduced to about 50 ml. The reaction mixture was cooled to room temperature, 300 ml of ice-cooled water was added, and the mixture was extracted 4 times with 150 ml dichloromethane. The combined organic phase was washed with water and the solvent was removed under reduced pressure. The obtained residue was dissolved in 500 ml of a 90:10:5 (v/v) mixture of methanol:water:concentrated hydrochloric acid, and the resulting solution was refluxed for 2 hours. After cooling to room temperature, 200 ml water was added. The product was extracted thrice with 200 ml chloroform, and washed consecutively with 200 ml water, 200 ml of a saturated aqueous sodium carbonate solution, and again with 200 ml water. The solvent was removed under reduced pressure and the product was crystallized from 450 ml petroleum ether at 4° C., yielding 69.93 grams of pure (S)-1-hexadecyl-sn-glycerol. The yield was 73%.

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