反应详情

A mixture of 189.7 g. of 4-carbomethoxy-1-cyclohexanone [3] (obtained as in Example 2B) in 2000 ml. of benzene, 67.5 ml. of ethylene glycol and 2.7 g. of p-toluenesulfonic acid is heated at reflux under a Dean-Stark trap for about 5 hours. After cooling, the solution is washed with saturated aqueous sodium bicarbonate and brine. The oily residue remaining when the organic solvent is evaporated to dryness and is distilled under vacuum to give 231.8 g. of 4-carbomethoxy-1-cyclohexanone ethylene ketal[4] having a boiling point of 95° to 100° C. at 0.30 mm. of Hg.

1. additionA mixture of 189.7 g
2. temperatureat reflux under a Dean-Stark trap for about 5 hours
3. temperatureAfter cooling
4. washthe solution is washed with saturated aqueous sodium bicarbonate and brine
5. customis evaporated to dryness
6. distillationis distilled under vacuum
7. customto give 231.8 g