Facile and Efficient Syntheses of Novel (S)- and (R)-3-Fluoropyrrolidines and 3,3-Difluoropyrrolidine

Abstract

Novel enantiomeric 3-fluoropyrrolidines and 3,3-difluoropyrrolidine were obtained in high yield starting from the enantiomerically pure and commercially available (2S,4R)-4-hydroxyproline. Spray-dried potassium fluoride and diethylaminosulfur trifluoride (DAST) were used to introduce one or two fluorine atoms, respectively.