反应详情

温度

-10 °C

75 ml of dry tetrahydrofuran and 23 g of magnesium shavings are added to a round flask which is fitted with a stirrer, thermometer, dropping funnel and reflux condenser. Without stirring there is added thereto slowly (within 4 hours) a solution of 112.4 g of 1-methyl-2-chloromethyl-3-(prop-1-en-2-yl)-cyclopent-1-ene in 100 ml of tetrahydrofuran. The mixture is brought to 60°-65° for 1 hour and then cooled to -10°. A carbon dioxide stream is conducted through the solution, which is cooled to -10° C. The amount of carbon dioxide introduced is weighed; it amounts to 29.5 g. The mixture is left to stand at room temperature overnight. The mixture is then cooled to 10° C. and decomposed with 300 ml of a 10% hydrochloric acid solution. The acid solution is extracted with ether, the organic acid formed is taken up as the sodium salt (treatment with 10% sodium hydroxide) from the ether into the aqueous phase, which is washed with ether. After acidifying with 10% orthophosphoric acid, the mixture is extracted with ether and the etherial solution is dried over sodium sulphate. The solvent is evaporated and there are obtained 78.2 g (yield: 66%) of crude 3-isopropenyl-2-methylene-1-methyl-cyclopentanecarboxylic acid, which are recrystallized with hexane.

1. customis fitted with a stirrer
2. temperaturereflux condenser
3. additionis added
4. customslowly (within 4 hours)
5. temperaturecooled to -10°
6. waitThe mixture is left
7. waitto stand at room temperature overnight
8. temperatureThe mixture is then cooled to 10° C.
9. extractionThe acid solution is extracted with ether
10. customthe organic acid formed
11. washis washed with ether
12. extractionthe mixture is extracted with ether
13. dry with materialthe etherial solution is dried over sodium sulphate
14. customThe solvent is evaporated