反应详情

To a solution of 4′-bromovalerophenone (2.41 g, 10 mmol) in benzene (60 ml) was added ethylene glycol (2.0 ml, 36 mmol), p-toluenesulfonic acid monohydrate (100 mg, 0.53 mmol) and the mixture refluxed under nitrogen in a Dean-Stark apparatus for 16 h. The reaction mixture was washed with sodium bicarbonate solution (5%, 50 ml), brine (1×50 ml), dried (Na2SO4) and evaporated to give 2-(4-bromophenyl)-2-butyl-1,3-dioxolane (11) as a clear oil (2.61 g, 92%). 1H nmr (CDCl3, 300 MHz) 0.88, t (6.9 Hz), H4″; 1.2-1.4, m, H2″,3″; 1.88, m, H1″; 3.7-3.8, m, CH2O; 4.0-4.1, m, CH2O; 7.34, d (8.4 Hz), H2′,6′; 7.49, d (8.4 Hz), H3′,5′. ESI (+ve) MS m/z 285/287 (M+H, 8%).

1. temperaturethe mixture refluxed under nitrogen in a Dean-Stark apparatus for 16 h
2. washThe reaction mixture was washed with sodium bicarbonate solution (5%, 50 ml), brine (1×50 ml)
3. dry with materialdried (Na2SO4)
4. customevaporated