Tert-butyl 2-(fluorocarbonyl)pyrrolidine-1-carboxylate → (R)-2-(2-ethoxy-5-oxo-2,5-dihydrofuran-3-ylcarbamoyl)-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 4-amino-5-ethoxy-5H-furan-2-one (0.05 g, 0.35 mmol) and 2-fluorocarbonyl-pyrrolidine-1-carboxylic acid tert-butyl ester (0.09 g, 0.42 mmol) in tetrahydrofuran (5 mL) at room temperature under nitrogen was added sodium tert-butoxide(0.05 g, 0.49 mmol). The reaction was stirred 3 h at reflux. After cooling, the mixture was diluted with ethyl acetate, was washed with 10% potassium bisulfate, saturated sodium bicarbonate, and brine, was dried over sodium sulfate, and was evaporated. Purification by flash chromatography (SiO2) eluted with 4:6 ethyl acetate:hexanes afforded (R)-2-(2-ethoxy-5-oxo-2,5-dihydrofuran-3-ylcarbamoyl)-pyrrolidine-1-carboxylic acid tert-butyl ester (0.075 g, 63% yield). Also recovered was starting 4-amino-5-ethoxy-5H-furan-2-one (0.016 g, 32% yield).

Provenance & Evidence