[S:1]1[CH:5]=[CH:4][C:3](/[CH:6]=[CH:7]/[CH:8]=[CH:9]/[CH2:10]O)=[CH:2]1.P(Br)(Br)Br.C([O:19][CH2:20][CH3:21])(=O)C>>[S:1]1[CH:5]=[CH:4][C:3](/[CH:6]=[CH:7]/[CH:8]=[CH:9]/[CH2:10][C:4]2[CH:5]=[C:21]([CH:7]=[CH:6][CH:3]=2)[CH:20]=[O:19])=[CH:2]120 mg of the resulting alcohol compound was dissolved in 1.5 ml of ethyl acetate, and under ice cooling, an ethyl acetate solution (0.5 ml) of 16.2 mg of phosphorus tribromide was added dropwise. The mixture was stirred for 1 hour, and then the solvent was evaporated. The residue was dissolved in 3 ml of toluene, and under a nitrogen atmosphere, 59 mg of 3-(tributylstannyl)benzaldehyde and 3 mg of tetrakis(triphenylphosphine)palladium were added. After the mixture was refluxed for 3 hours, 1 ml of a saturated aqueous solution of potassium fluoride was added, and the mixture was stirred at room temperature for 30 minutes. Water and ethyl acetate were added, and the organic layer separated was worked up in a customary manner. The product was purified by medium-pressure liquid chromatography [hexane/ethyl acetate=8/1] to give 7 mg of (E,E)-3-[5-(3-thienyl)-2,4-penta-dienyl]benzaldehyde as a pale yellow oil.
読み込み中…