C1COCC1.[Br-].[F:7][CH2:8][CH2:9][CH2:10]P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.CC(C)([O-])C.[K+].[F:36][C:37]1[CH:38]=[C:39]([CH:47]2[CH2:52][CH2:51][C:50](=O)[CH2:49][CH2:48]2)[CH:40]=[C:41]([F:46])[C:42]=1[O:43][CH2:44][CH3:45]>O>[F:36][C:37]1[CH:38]=[C:39]([CH:47]2[CH2:52][CH2:51][CH:50]([CH2:10][CH2:9][CH2:8][F:7])[CH2:49][CH2:48]2)[CH:40]=[C:41]([F:46])[C:42]=1[O:43][CH2:44][CH3:45]THF (100 ml) was added to the above 3-fluoropropyltriphenylphosphine bromide (22.0 g, 54.6 mmol), followed by cooling the mixture down to -50° C. in a nitrogen atmosphere, adding to the mixture, a 70 ml THF solution of potassium-t-butoxide (6.10 g, 54.5 mmol), stirring the mixture for 3 hours, dropwise adding to the reaction solution, a 80 ml THF solution of 4-(3,5-difluorophenetyl)-1-cyclohexanone (10.0 g, 42.0 mmol), stirring the mixture for one hour at the same temperature, and heating it up to room temperature for 4 hours, adding water (200 ml) to the resulting reaction solution, extracting the resulting product with ethyl acetate, washing the extraction solution successively with a saturated aqueous solution of sodium bicarbonate and water, drying the organic layer over magnesium sulfate, distilling off the solvent under reduced pressure, purifying the residue according to column chromatography treatment using toluene as a developing solvent, hydrogenating the resulting purified substance in the presence of 5% Pd/C catalyst, in ethanol, and thereafter filtering off the catalyst to obtain 4-(3,5-difluorophenetyl)-1-(3-fluoropropyl)cyclohexane (2.51 g, 8.83 mmol). Yield: 21.0%.
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