Isopropanol → 6,6-dimethylhept-1-en-4-yn-3-ol

Participants

Reaction Conditions

Reaction Steps

Under a blanket of dry nitrogen, at 0° C., metallic lithium (0.667 gr., 0.096 mole) was added to a mixture of t-butylacetylene (9.94 gr., 0.121 mole) and tetrahydrofuran (75 ml). The mixture was heated to 40° C. for 5 hours and kept at room temperature for 24 hours. The lithium was almost completely consumed. A second amount of t-butylacetylene (9.94 gr., 0.121 mole) was added and the reaction mixture was stirred for 21 hours. The mixture was cooled to 0° C. and a solution of freshly distilled acrolein (6.634 gr., 0.118 mole) in tetrahydrofuran (10 ml) was added gradually during 30 minutes. The mixture was stirred at 0° C. for 30 minutes and then at room temperature for 3 hours. Isopropanol (6 ml) was added to quench the remaining lithium. The mixture was quenched using saturated ammonium chloride aqueous solution (30 ml) at 0° C. The pH was brought to 6 by 10% sulfuric acid (ca. 45 ml). The tetrahydrofuran and excess t-butylacetylene were evaporated and the mixture was extracted 3 times by dichloromethane (70 ml each time). The organic phase was washed with water (2×20 ml), dried and the solvent evaporated to give 10.2 gr. of an almost pure 6,6-dimethylhept-1-en-4-yn-3-ol (73.9% yield).

Provenance & Evidence