60298-18-2

87121-89-9

60298-18-2

GENERAL METHOD: To a solution of ethyl 3-oxocyclobutanecarboxylate (100 mg, 0.45 mmol) in dichloromethane (3.8 mL) was slowly added hydrogen chloride (2 M, 1.4 mL) at room temperature. Subsequently, O- homotrimethylbenzenesulfonylhydroxylamine (2.00 equiv, 2.0000) was added and the reaction mixture was stirred for 3 hours. After completion of the reaction, saturated NaHCO3 solution was added for neutralization and the organic layer was extracted with dichloromethane. The organic layers were combined, dried over anhydrous sodium sulfate and subsequently concentrated under reduced pressure. The crude product was purified by rapid chromatography on silica gel to afford ethyl 5-oxopyrrolidine-3-carboxylate (87 mg, 0.802 mmol, 80% yield) as a white solid.