[CH3:1][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][CH:9]=1)[CH:5]=O.[CH3:10][C:11]([CH3:13])=[O:12].[OH-].[Na+].O>C(O)C>[CH3:1][C:2]1[CH:3]=[C:4]([CH:5]=[CH:10][C:11](=[O:12])[CH:13]=[CH:1][C:2]2[CH:9]=[CH:8][CH:7]=[C:4]([CH3:5])[CH:3]=2)[CH:7]=[CH:8][CH:9]=13-Methylbenzaldehyde (1ab, 3.00 ml, 25.4 mmol) and acetone (19, 0.94 ml, 12.7 mmol) were combined in ethanol (20 ml) and stirred for 15 min at room temperature. A solution of sodium hydroxide (1.50 g, 37.5 mmol) and water (20 ml) was added and the mixture stirred for 18 hr at room temperature. The resulting mixture was extracted into ethyl acetate, washed with saturated sodium chloride, dried over magnesium sulfate, filtered and evaporated to afford a solid. The crude solid was recrystallized from ethanol to give 2.39 g (72%) of a yellow solid: mp 68-72° C. [expected mp 68-72° C.]; 1H NMR: δ 2.38 (s, 6H), 7.06 (d, 2H, J=15.9 Hz), 7.26 (m, 4H), 7.40 (m, 4H), 7.70 (d, 2H, J=15.9 Hz); 13C NMR: δ 21.3, 125.1, 125.4, 128.6, 128.8, 131.1, 134.6, 138.4, 143.1, 188.6.
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