ethyl 3-[4-(3-ethoxy-3-oxopropyl)phenyl]propanoate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: First, 2.78 g of 1,4-bis(2-ethoxycarbonylethyl)benzene was dissolved in 40 ml of absolute toluene, the solution was cooled to -65° C. with dry ice/acetone, and a solution of 1M diisobutylammonium hydride in 24 ml of toluene was added dropwise with stirring over 25 minutes, and the mixture was further stirred at -70° C. for 2 hours. Next, 2.5 ml of ethanol/2.5 ml of toluene, 3 ml of ethanol, and 2.75 ml of water/5.5 ml of ethanol were added dropwise in this order, and after removing cooling bath, the mixture was allowed to warm to a room temperature with stirring. After adding 10 ml of water, the mixture was adjusted to a pH value of not more than 3 with 6N hydrochloric acid. The organic layer was separated, washed with water and a saturated sodium chloride aqueous solution, dried over magnesium sulfate, and evaporated under a reduced pressure. The residue was applied to a silica gel column and eluted with hexane/ethyl acetate (6:1) to obtain 988 mg of 1,4-bis(2-formylethyl)benzene as a colorless crystal. the mixture was further stirred at -70° C. for 2 hours after removing cooling bath with stirring After adding 10 ml of water The organic layer was separated washed with water a saturated sodium chloride aqueous solution, dried over magnesium sulfate evaporated under a reduced pressure eluted with hexane/ethyl acetate (6:1)