反应详情

A solution of 7.2 g (48.6 mmole) of (S)-2-mercapto-4 methylpentanoic acid [J. A. Yankeelov, Jr., K. F. Fok, and D. J. Carothers, J. Org Chem., 43, 1623 (1978)] and 219 mg of p-toluenesulfonic acid in 12 ml of absolute ethanol and 12 ml of CHCl3 was stirred under reflux with collection of liberated H2O in a Dean-Stark trap pre-filled with CHCl3. After 4 hours, the solution was cooled, diluted with an equal volume of CHCl3, and washed successively with H2O, saturated aqueous NaHCO3 solution, and H2O. The organic phase was dried over MgSO4, filtered, and concentrated to give 6.90 g (81%) of an oil, [α]20D -19.0° (c 2, ether), TLC in 9:1 hexane-ethyl acetate. The structure was verified by 200 MHz NMR (CDCl3).

1. temperaturethe solution was cooled
2. washwashed successively with H2O, saturated aqueous NaHCO3 solution, and H2O
3. dry with materialThe organic phase was dried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated