Water → 4-[2-(p-Pentylphenyl)ethenyl]cyclohexanecarbonitrile

A mixture of 2.51 g of p-pentylbenzyl-triphenylphosphonium bromide and 615 mg of a cis/trans mixture (about 1:1) of 4-cyanocyclohexanecarboxaldehyde in 30 ml of t-butyl methyl ether was placed at 0° C. under argon gasification in a sulphonation flask fitted with a thermometer and solid substance addition tube, treated within 2 minutes with 673 mg of solid potassium t-butylate and subsequently stirred for a further 1.5 hours. The red-brown heterogeneous mixture was then poured into 100 ml of water and extracted three times with 100 ml of diethyl 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. The residue was suspended in 150 ml of hexane, freed from precipitated triphenylphosphine oxide by filtration (rinsing with hexane) and the filtrate was concentrated. Low-pressure chromatography (0.4 bar) of the resulting oil (1.36 g) on silica gel using 3% ethyl acetate/petroleum ether as the eluting agent gave 1.02 g (81%) of 4-[2-(p-pentylphenyl)ethenyl]cyclohexanecarbonitrile as a colourless oil; Rf values (10% ethyl acetate/petroleum ether): 0.27 and 0.37 (stereoisomer mixture).