反应详情

20.06 Grams (0.418 mole) of 50% sodium hydride dispersion was introduced into a 1 liter four-necked flask equipped with a thermometer, a tap funnel, a reflux cooler and a stirrer and washed with benzene. Then 500 ml of pure tetrahydrofuran and 20 ml of t-BuOH were added thereto and the mixture was refluxed for 30 mins. During the reflux, there was dropwise added 150 ml of pure tetrahydrofuran containing dissolved therein 61.87 g (0.340 mol) of cyclododecanone and 86.0 g (0.374 mol) of di-tert-butyl succinate, over 1.5 hour. After that the reflux was continued to complete the reaction. After the reaction, a mixture of 100 ml of water and 78 ml of concentrated hydrochloric acid was added to the reaction product and the obtained mixture was concentrated. The solvent was removed and the product mixture was twice extracted with 250 ml of ether. The extract liquid was washed with water and dried, followed by concentration to obtain 115.1 g of crude β-cyclododecenyl-β-tert-butoxycarbonyl propionic acid II with the purity of 86.8% and the yield of 86.9%. The crude product was found to include about 2% of cyclododecanone and about 5% of high boiling point-having by-products and the balance of the impurities was solvents.

1. customequipped with a thermometer, a tap funnel
2. washa reflux cooler and a stirrer and washed with benzene
3. additionThen 500 ml of pure tetrahydrofuran and 20 ml of t-BuOH were added
4. temperaturethe mixture was refluxed for 30 mins
5. dissolutiondissolved
6. customthe reaction
7. customAfter the reaction
8. additionwas added to the reaction product
9. concentrationthe obtained mixture was concentrated
10. customThe solvent was removed
11. extractionthe product mixture was twice extracted with 250 ml of ether
12. washThe extract liquid was washed with water
13. customdried
14. concentrationfollowed by concentration