Into a flask, were placed triphenylphosphine (2.9 g, 11 mmol) and 3-fluoro-4-bromophenethylbromide (2.2 g, 11 mmol) prepared from 3-fluoro-4-bromophenethylalcohol, followed by adding and dissolving xylene (15 ml), heating under reflux for 10 hours, adding THF (10 ml) to the reaction solution and stirring under ice-cooling, adding potassium-t-butoxid (1.1 g, 10 mmol) slowly to the reaction solution, stirring the reaction solution after the completion of dropping at room temperature for 2 hours, adding THF (10 ml) solution of 4-(ethylcyclohexyl) cyclohexylacetoaldehyde (2.4 g, 10 mmol), further stirring for 5 hours, adding ether after the completion of reaction, filtering off white solid deposited, concentrating the filtrate under reduced pressure, purifying the obtained brown oil by means of silica gel chromatography, to obtain a mixture (1.8 g, 4.2 mmol) of 1-(3-fluoro-4-bromophenyl)-4-(4-(4-ethylcyclohexyl)cyclohexyl)-2-Z-butene with its E-isomer.
