反应详情

In a 100 ml. three-necked flask fitted with a mechanical stirrer and a Dean-Stark water separator provided with a reflux condenser, a solution of 7 g. of 2,6,6-trimethyl-3-acetoxy-1-(3-acetoxy-but-1-ynyl)cyclohex-1ene in 70 ml. of methylene chloride is refluxed while stirring. Then 0.7 g. of p-toluenesulfonic acid is added and the reaction mixture is refluxed for an additional 7 hours. The reaction mixture is cooled and then poured into 70 ml. of water. The organic layer is separated, washed with 10% sodium bicarbonate solution and water. Drying over sodium sulfate and subsequent concentration yields 5 g. of a residue which gives, upon distillation using a short Vigreux column, 3 g. or 60% yield of 1-crotonoyl-2,6,6-trimethylcyclohexa-1,3-diene, b.p. 75°-80° C./0.1 mm, nD20 1.5150.

1. customthree-necked flask fitted with a mechanical stirrer
2. temperaturethe reaction mixture is refluxed for an additional 7 hours
3. temperatureThe reaction mixture is cooled
4. additionpoured into 70 ml
5. customThe organic layer is separated
6. washwashed with 10% sodium bicarbonate solution and water
7. dry with materialDrying over sodium sulfate and subsequent concentration
8. customyields 5 g
9. customof a residue which gives, upon distillation