反应详情

温度

-70 °C

Anhydrous ethyl ether (11 cc) and 1-bromo-2-methyl-4-trimethylsilyloxy-1,3-butadiene (0.9 g) are introduced under an argon atmosphere into a 50-cc round-bottomed flask. This is cooled to -70° C. and then a solution (3.25 cc) of 1.65M tert-butyllithium in pentane is added over 10 minutes. The mixture is stirred at -70° C. for 100 minutes and 3,3-ethylenedioxybutanal (0.4 g) is then added in solution in anhydrous ethyl ether (4 cc). The temperature is allowed to rise to -30° C. and stirring is performed for 30 minutes. Further stirring is performed for 20 minutes at -20° C. and then the mixture is cooled to -60° C. N Hydrochloric acid (11.5 cc) is added over 20 minutes. The temperature is allowed to rise to about 20° C. After the reaction mixture has been taken up with ether and water and the organic phases have been dried over magnesium sulphate, and after flash chromatography, 7,7-ethylenedioxy-3-methyl-2,4-octadienal (0.33 g) is obtained, its characteristics being as follows:

1. customto rise to -30° C.
2. stirringstirring
3. waitis performed for 30 minutes
4. stirringFurther stirring
5. waitis performed for 20 minutes at -20° C.
6. temperaturethe mixture is cooled to -60° C
7. customto rise to about 20° C
8. dry with materialthe organic phases have been dried over magnesium sulphate