Sulfuric Acid → (E)-6-(4-chlorophenyl)-2,4-dioxo-hex-5-enoic acid methyl ester
反応式
[CH2:1]([O:3][C:4](=[O:19])[C:5](=[O:18])[CH2:6][C:7](=[O:17])/[CH:8]=[CH:9]/[C:10]1[CH:15]=[CH:14][C:13]([Cl:16])=[CH:12][CH:11]=1)C.OS(O)(=O)=O>CO>[CH3:1][O:3][C:4](=[O:19])[C:5](=[O:18])[CH2:6][C:7](=[O:17])/[CH:8]=[CH:9]/[C:10]1[CH:11]=[CH:12][C:13]([Cl:16])=[CH:14][CH:15]=1参加物
4
実験手順
A solution of (E)-6-(4-chlorophenyl)-2,4-dioxo-hex-5-enoic acid ethyl ester (4; 33.39 g, 0.12 mol) and conc H2SO4 (0.5 mL) was stirred at reflux for 6 h in methyl alcohol (MeOH, 400 mL). Upon cooling and solvent concentration, (E)-6-(4-chlorophenyl)-2,4-dioxo-hex-5-enoic acid methyl ester (6; 22.7 g, 71%) was collected as yellow crystals: mp 135-136° C.; 1H NMR (400 MHz, CDCl3) δ 14.74 (s, 1H), 7.67 (d, J=15.9 Hz, 1H), 7.49 (d, J=8.5 Hz, 2H), 7.38 (d, J=8.5 Hz, 2H), 6.61 (d, J=15.9 Hz, 1H), 6.53 (s, 1H), 3.92 (s, 3H); HRMS-ESI (m/z): calcd for C13H1ClO4, 266.034. found, 266.034.