反应详情

30 g of acrolein (boiling point about 105° C) are added dropwise in the course of 60 minutes to 150 g of ethyl isopropyl ketone and 2 g of p-toluenesulfonic acid, under reflux. The water formed is removed. After 3 hours, the unconverted starting materials are distilled off through a short column under atmospheric pressure at from 40° to 112° C. The reaction mixture ist then kept for 1 hour at an internal temperature of 200° C and is thereafter distilled under reduced pressure. 7 g of water, 3 g of acrolein, 122 g of ethyl isopropyl ketone, 22 g of 2,6,6-trimethyl-cyclohex-2-en-1-one (free from isomers) and 28 g of residue are obtained. This amounts to a yield of 57%, based on ethyl isopropyl ketone employed.

1. temperatureunder reflux
2. customis removed
3. distillationthe unconverted starting materials are distilled off through a short column under atmospheric pressure at from 40° to 112° C
4. waitThe reaction mixture ist then kept for 1 hour at an internal temperature of 200° C
5. distillationis thereafter distilled under reduced pressure