C([O:3][C:4](=[O:32])[CH:5]=[CH:6][C:7]1[S:11][C:10]2[CH:12]=[CH:13][CH:14]=[C:15]([C:16]3[CH:21]=[C:20]([CH:22]([CH3:24])[CH3:23])[CH:19]=[C:18]([CH:25]([CH3:27])[CH3:26])[C:17]=3[O:28][CH2:29][CH2:30][CH3:31])[C:9]=2[CH:8]=1)C.C1COCC1.[Li+].[OH-]>CO>[CH2:29]([O:28][C:17]1[C:18]([CH:25]([CH3:27])[CH3:26])=[CH:19][C:20]([CH:22]([CH3:23])[CH3:24])=[CH:21][C:16]=1[C:15]1[C:9]2[CH:8]=[C:7]([CH:6]=[CH:5][C:4]([OH:32])=[O:3])[S:11][C:10]=2[CH:12]=[CH:13][CH:14]=1)[CH2:30][CH3:31]A mixture of 0.450 mmol of 3-[4-(2-n-propoxy-3,5-di-iso-propylphenyl)-benzo[b]thien-2-yl]-prop-2-enoic acid ethyl ester, 3 mL of THF, 3 mL of methanol and 1 mL of LiOH (2N aqueous) was refluxed for 2 hours. After cooling at room temperature, the mixture was acidified to pH=2 and extracted with ethyl acetate. The organic layer was dried over MgSO4 and after evaporation of the solvents, the crude acid was recrystallized from acetonitrile. (E) 3-[4-(2-n-propoxy-3,5-di-iso-propylphenyl)-benzo[b]thien-2-yl]-prop-2-enoic acid was isolated as a white solid.
読み込み中…