101385-93-7

83220-73-9

101385-93-7

General procedure for the synthesis of 1-tert-butoxycarbonyl-3-hydroxy-pyrrolidine from 1-tert-butoxycarbonyl-3-pyrrolidinone: To a dichloromethane (20 mL) solution of oxalyl chloride (2.8 mL, 32.4 mmol) a dichloromethane (40 mL) solution of dimethylsulfoxide (DMSO, 4.6 mL, 64.8 mmol) was slowly added at -78 °C, and subsequently the reaction mixture was stirred at -15 °C for 5 min. Next, a dichloromethane (60 mL) solution of N-Boc-3-pyrrolidinol (4.04 g, 21.6 mmol) was added at -78°C and stirring was continued for 2 hours at this temperature. Subsequently, triethylamine (15 mL, 108 mmol) was added to the reaction mixture and stirred at -78 °C for 1 hour. After that, the reaction mixture was slowly warmed to room temperature and stirring was continued for 2 hours at room temperature. After completion of the reaction, the mixture was cooled to 0 °C and the reaction was quenched with saturated sodium bicarbonate (NaHCO3) solution and diluted with ethyl acetate. The organic layer was washed sequentially with saturated sodium bicarbonate solution and saturated saline. The organic layers were combined, dried with anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure to afford the crude product 1-tert-butoxycarbonyl-3-pyrrolidinone (4 g, 100% yield), which could be used for subsequent reactions without further purification. The product was characterized by 1H NMR (400 MHz, CDCl3): δ 3.79-3.75 (m, 4H), 2.58 (t, J = 8.0 Hz, 2H), 1.47 (s, 9H).