Hexachloroethane → (Z)-3-chloro-6,6-dimethyl-2-hepten-4-yn-1-ol

Participants

Reaction Steps

A solution of lithium aluminum hydride (11.4 mmol; 1M solution in tetrahydrofuran, (hereafter THF) was added to a stirred suspension of sodium methoxide (1.23 g, 22.8 mmol) in 18 ml of dry THF and the mixture was stirred at room temperature for 1/2 hour. 6,6-Dimethyl-2,4-heptadiyn-1-ol (777 mg, 5.71 mmol) was added and the mixture stirred at room temperature overnight. The mixture was cooled to 0° C. and dry ethyl acetate (1.0 g, 11.4 mmole) was added dropwise. Hexachloroethane (4.05 g, 17.13 mmole) was then added and the mixture was allowed to warm to room temperature. After 4.5 hours, additional hexachloroethane (1.35 g, 5.71 mmol) was added to the reaction mixture which was then stirred for 68 hours. The mixture was partitioned between ether and dilute aqueous hydrochloric acid, and the aqueous layer was extracted 3 times with ether. The combined ethereal extract was washed with water an brine, dried over anhydrous sodium sulfate and concentrated in vacuo to afford 3.43 g of crude product. This mixture was purified by chromatography on a column (2.5×47 cm) of silica gel eluting with ethyl acetate-hexane, 5/95. Combination and concentration of the appropriate fractions afforded 404 mg of the desired (Z)-3-chloro-6,6-dimethyl- 2-hepten-4-yn-1-ol.

Provenance & Evidence