反应详情

5-oxo-alpha-hydroxy-2-pyrrolidinepropanoic acid (1.1 g), triethylamine (1.2 g), N-N-dimethylaminopyridine (1.5 g), and benzyl chloroformate (17 g) in 40 ml tetrahydrofuran is heated at reflux for 16 hours. After cooling and filtering off the triethylamine-hydrochloride, the solution was concentrated and chromatographed on SiO2 (elution with methanol:chloroform; 3:97) to yield 5-oxo-alpha-hydroxy-2-pyrrolidinepropanoic acid, benzyl ester mp 95°-96° C. NMR (CDCl3) and 7.37 (s, 5H), 7.93 (d, 1H), 5.40 (s, 1H), 1.70 (m, 2H). IR (KBr) 3330, 3200, 1733, 1691, 1497, 1456, 1389, 1351, 1287, 1216.

1. temperatureat reflux for 16 hours
2. temperatureAfter cooling
3. filtrationfiltering off the triethylamine-hydrochloride
4. concentrationthe solution was concentrated
5. customchromatographed on SiO2 (elution with methanol:chloroform; 3:97)