15401-08-8

52386-41-1

15401-08-8

GENERAL METHODS: 130 mg of N-Boc-D-Pro-L-Glu(OMe)-OMe (0.28 mmol) was dissolved in 3 cm3 methanol to which 0.7 cm3 1 M sodium hydroxide solution was added. The resulting reaction mixture was stirred at room temperature for 2 hours. After completion of the reaction, the reaction mixture was concentrated under reduced pressure. The concentrated aqueous phase was acidified with concentrated hydrochloric acid to pH 1. The aqueous phase was extracted with dichloromethane (3 x 7 cm3). The organic layers were combined, washed with saturated brine and dried over anhydrous sodium sulfate. Finally, the solvent was removed under reduced pressure to give the target product (S)-1-((S)-1-(tert-butoxycarbonyl)pyrrolidine-2-carbonyl)pyrrolidine-2-carboxylic acid.