Sulfuric Acid → 4,8,12-Trimethyltridec-2-yn-1,4-diol

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Reaction Conditions

Reaction Steps

Into a 2-liter, three-neck, round-bottom flask fitted with a mechanical stirrer, a reflux condenser, and an addition funnel was added 210 g (3.60 mol) of finely powdered potassium hydroxide and 500 ml of anhydrous tetrahydrofuran. The resulting reaction mixture was heated to reflux and then 30.0 g (0.54 mol) of propargyl alcohol was slowly added over a 30 minute period with rapid stirring. The mixture was refluxed for 3 hours before 100 g (0.51 mol) of hexahydropseudoionone in 140 ml of tetrahydrofuran was slowly added over a 2-hour period. After an additional 2 hours at reflux, the reaction was cooled to 0° C. and poured onto 1000 g of ice and 360 g of concentrated sulfuric acid with efficient mixing. The resulting aqueous layer was rinsed with 3×100 ml of ether and the combined organic layers were rinsed with 50 ml of water, 3×50 ml of saturated aqueous sodium bicarbonate, and 50 ml of brine. The resulting ethereal solution was dried with 50 g of magnesium sulfate, and the solvent was removed at aspirator pressure with the aid of a rotary evaporator, leaving 110 g of crude product. Vacuum distillation at 40 μHg and 140° C. afforded 92 g (73%) of pure product, i.e. 4,8,12-trimethyltridec-2-yn-1,4-diol.

Provenance & Evidence