Carbon tetrabromide → HCID 22279681, compound

Subsequently, to a solution of carbon tetrabromide (36.5 g, 0.11 mol) in dichloromethane (120 ml) was added a solution of triphenylphosphine (57.7 g, 0.22 mol) in dichloromethane (120 ml) with stirring while ice-cooling under a nitrogen atmosphere, and the resulting mixture was stirred for 5 minutes. After stirring, to the reaction mixture was added a solution of the crude 3-cyclohexyloxypropionaldehyde (8.60 g) obtained above in dichloromethane (90 ml) with stirring while ice-cooling under a nitrogen atmosphere, and the resulting mixture was stirred at the same temperature for 25 minutes. After stirring, the reaction mixture was diluted with dichloromethane and washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. After filtration, the solvent was removed in vacuo, and the residue was purified by chromatography on a silica gel column using a mixed solvent of hexane and ethyl acetate (100:1-33:1) as the eluent to afford 4-cyclohexyloxy-1,1-dibromobut-1-ene (12.6 g, overall yield in two steps: 55%).