L-Pyroglutaminol

7149-65-7

17342-08-4

General procedure for the synthesis of (S)-(+)-5-hydroxymethyl-2-pyrrolidinone from ethyl (S)-5-oxopyrrolidine-2-carboxylate: compound III was synthesized as follows: firstly, LiCl (18 mmol) was added to the reaction flask and dissolved in anhydrous tetrahydrofuran (15 ml). The temperature of the reaction system was controlled at -15 to -10°C. Subsequently, potassium borohydride (18 mmol) was added to the system and the reaction was stirred for 30 minutes. In another reaction flask, compound II (9 mmol) was dissolved in anhydrous tetrahydrofuran (20 ml) and cooled to -15 to -10 °C. Then, the previously prepared reaction solution was slowly added dropwise to this system. After the dropwise addition, the reaction was slowly warmed up to room temperature for 2 hours. The reaction process was monitored by TLC to confirm the complete reaction of the raw materials. Next, saturated ammonium chloride solution (5 ml) was added slowly dropwise to the reaction system and stirred for 30 minutes. The reaction mixture was extracted with ethyl acetate, the organic phases were combined and dried with anhydrous sodium sulfate. The dried organic phase was filtered and the filtrate was concentrated under reduced pressure to give compound III (8.55 mmol) in 95% yield.