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 5 g. of 2,6,6-trimethyl-1-(3-acetoxy-but-1-ynyl)cyclohexa-1,3-diene in 70 ml. of methylene chloride is refluxed while stirring. Then 0.2 g. of p-toluenesulfonic acid is added and the reaction mixture is refluxed for an additional 4 to 5 hours. The reaction mixture is cooled and poured into 70 ml. of water. The organic layer is separated, subsequently washed with 10% sodium bicarbonate solution and water, and finally dried over sodium sulfate. Concentration yields 5 g. of a residue which gives on distillation 2.5 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 4 to 5 hours
3. temperatureThe reaction mixture is cooled
4. additionpoured into 70 ml
5. customThe organic layer is separated
6. washsubsequently washed with 10% sodium bicarbonate solution and water
7. dry with materialfinally dried over sodium sulfate
8. concentrationConcentration
9. customyields 5 g
10. customof a residue which gives on distillation 2.5 g