Water → HCID 178455747, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 2.66 g of trans-1-(2,2-dibromovinyl)-4-[2-(trans-4-pentylcyclohexyl)ethyl]cyclohexane in 120 ml of absolute tetrahydrofuran was placed at -78° C. in a sulphonation flask under argon gasification and treated within 10 minutes with 15.2 ml of a 0.1N solution of butyl lithium in hexane. After completion of the addition, the mixture was stirred at -78° C. for a further 2 hours, then poured into 100 ml of water and extracted three times with 100 ml of petroleum ether each time. The organic phases were washed twice with 50 ml of water each time and once with 50 ml of saturated sodium chloride solution, dried over magnesium sulphate and concentrated. Low-pressure chromatography (0.5 bar) of the residue (1.90 g) on silica gel with hexane gave 1.48 g (88%) of trans-1-ethynyl-4-[2-(trans-4-pentylcyclohexyl)ethyl]cyclohexane as a trans/cis epimer mixture (about 9:1). Fractional crystallization from 50 ml of methanol yielded 883 mg of pure trans-1-ethynyl-4-[2-(trans-4-pentylcyclohexyl)ethyl]cyclohexane as colourless crystals; m.p. (C-N) 51.3° C., cl.p. (N-I) 68.0° C.

Provenance & Evidence