反应详情

First, 25.7 g of 3-ethoxycarbonylpropyltriphenylphosphonium bromide, 10.1 g of trans-4-(2,3-difluorophenyl)cyclohexanecarbaldehyde, and 150 ml of dry tetrahydrofuran were placed in a 300 ml flask. Then, 56.3 ml of 1.0M sodium bis(trimethylsilyl)amide/tetrahydrofuran solution was added dropwise to the reaction mixture at -70° C. to -60° C. The reaction mixture was stirred while being allowed to warm to room temperature over 6 hours. Ether was added to the reaction mixture. The ether solution was washed with water and dried over anhydrous sodium sulfate. Thereafter, the solvent was distilled away. The residue was purified by silica gel column chromatography (eluent: toluene/hexane=1/1) to obtain 9.0 g of 2,3-difluoro-1-[trans-4-(4-ethoxycarbonyl-1-butenyl)cyclohexyl]benzene (Y: 62%). The compound thus obtained had a purity of 89.2% (mixture of E and Z isomers) by GC.

1. washThe ether solution was washed with water
2. dry with materialdried over anhydrous sodium sulfate
3. distillationThereafter, the solvent was distilled away
4. customThe residue was purified by silica gel column chromatography (eluent: toluene/hexane=1/1)