反应详情

15.20 g (110 mmol) of potassium carbonate and 0.46 g (2 mmol) of benzyltriethylammonium chloride are suspended in 100 ml of acetonitrile. While stirring there are added thereto 21.60 g (100 mmol) of methyl 4-methoxy-2-[1 -methylacetonyl]-acetoacetate, the mixture is heated to 60° C. and 28.39 g (200 mmol) of methyl iodide are added dropwise thereto within 30 minutes. The mixture is stirred at 60° C. for a further 16 hours; then 6.91 g (50 mmol) of potassium carbonate and 7.10 g (50 mmol) of methyl iodide are again added and the mixture is stirred at 60° C. for a further 21 hours. 6.90 g (50 mmol) of potassium carbonate in 300 ml of distilled water are now added thereto. The reaction mixture is held at reflux temperature for 6 hours. It is then extracted 3 times with 100 ml of ether each time. The combined organic phases are dried over magnesium sulphate and concentrated on a rotary evaporator. The crude product distils at 70°-78° C./12 mm and yields 6.03 g (39.2%) of 2-methoxy-3,4,5-trimethyl-2-cyclopenten-1-one.

1. additionare added
2. stirringThe mixture is stirred at 60° C. for a further 16 hours
3. stirringthe mixture is stirred at 60° C. for a further 21 hours
4. temperatureat reflux temperature for 6 hours
5. extractionIt is then extracted 3 times with 100 ml of ether each time
6. dry with materialThe combined organic phases are dried over magnesium sulphate
7. concentrationconcentrated on a rotary evaporator
8. customThe crude product distils at 70°-78° C./12 mm