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A suspension of 3.16 g of ethyl-triphenylphosphonium bromide in 50 ml of dry t-butyl methyl ether was treated with 960 mg of potassium t-butylate while gassing with argon at -10° C. and the mixture was stirred for a further 45 minutes at 0° C. Thereafter, the mixture was cooled to -20° C., treated within 5 minutes with a solution of 1.45 g of 4-[trans-4-(p-cyanophenyl)cyclohexyl]butyraldehyde (purity 90%) in 20 ml of t-butyl methyl ether and the mixture was stirred for a further 30 minutes while warming to room temperature. The reaction mixture was subsequently poured into 100 ml of water and extracted three times with 100 ml of diethyl ether each time. The organic phases were washed with 100 ml of water, dried over magnesium sulphate and concentrated. Low-pressure chromatography (0.5 bar) of the residue on silica gel with ethyl acetate/petroleum ether (vol. 3:97) gave p-[trans-4-(4-hexenyl)cyclohexyl]benzonitrile (4Z: 4E=88:12) as a colourless oil. Additional low-pressure chromatography (0.5 bar) of this material on 140 g of silver nitrate-coated silica gel (prepared according to Example 2) with hexane/diethyl ether (vol. 3:1) yielded 750 mg of p-[trans-4-(4Z-hexenyl)cyclohexyl]benzonitrile. Two-fold recrystallization from methanol finally gave 468 mg of colourless crystals with m.p. (C-I) 27.4° C. and cl.p. (N-I) 4.5° C.

1. customwhile gassing with argon at -10° C.
2. temperatureThereafter, the mixture was cooled to -20° C.
3. stirringthe mixture was stirred for a further 30 minutes
4. temperaturewhile warming to room temperature
5. extractionextracted three times with 100 ml of diethyl ether each time
6. washThe organic phases were washed with 100 ml of water
7. dry with materialdried over magnesium sulphate
8. concentrationconcentrated