反应详情

温度

90 °C

To (4S,5R)-4-benzyl-2-oxo-5-oxazolidinecarboxylic acid obtained in the same manner as in Example 4 (2.39 g) were added 2-propanol (6.7 ml) and 8N aqueous potassium hydroxide solution (6.7 ml), and the mixture was stirred at 90° C. for 3 hr. The mixture was cooled to room temperature and adjusted to pH=8 with 6N aqueous hydrochloric acid solution. To the reaction mixture was added di-tert-butoxycarbonate (2.83 g) dissolved in 2-propanol (6.7 ml) and the mixture was stirred at room temperature for 12 hr. After adjusting the mixture to pH=3, dichloromethane (20 ml) was added to extract the mixture. The solvent of the organic layer was removed under reduced pressure to give crude crystals of (2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-4-phenylbutyric acid (2.88 g). The crude crystals were analyzed by HPLC to confirm that (2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-4-phenylbutyric acid (2.55 g, yield 80%) was obtained.

1. temperatureThe mixture was cooled to room temperature
2. stirringthe mixture was stirred at room temperature for 12 hr
3. additionwas added
4. extractionto extract the mixture
5. customThe solvent of the organic layer was removed under reduced pressure