反应详情

100 g (0.5612 mol) of 4-(1,3-dioxolan-2-yl)-benzaldehyde and 56.1 g (0.56 mol) of pinacoline are dissolved in a mixture of 280 ml of ethanol and 56 ml of water, and 17 ml of 10% strength sodium hydroxide solution are added at room temperature. The mixture is subsequently stirred for 1 hour, 0.56 g of solid sodium hydroxide are added and the mixture is subsequently stirred for 2 days. Thereafter, the precipitate is filtered off with suction, washed with 200 ml of ethanol/water (1:1) and then with water, dried and recrystallized twice from ethanol. 56.5 g (39% of theory) of 4,4-dimethyl-1-[4-(1,3-dioxolan-2-yl)-phenyl]-1-penten-3-one of melting point 79°-81° C. are obtained.

1. additionare added at room temperature
2. stirringthe mixture is subsequently stirred for 2 days
3. filtrationThereafter, the precipitate is filtered off with suction
4. washwashed with 200 ml of ethanol/water (1:1)
5. dry with materialwith water, dried
6. customrecrystallized twice from ethanol