合成路线1

3-Fluorocinnamic acid (I) is activated as the mixed anhydride (II) with pivaloyl chloride and subsequently coupled to the lithium anion of (S)-4-benzyloxazolidin-2-one (III) to provide the N-acyl oxazolidinone (IV). Cycloaddition of the cinnamoyl derivative (IV) with N-methoxymethyl-N-trimethylsilylmethyl benzylamine (V) in the presence of trifluoroacetic acid gives rise to a diastereomeric mixture of trans-pyrrolidines (VI) and (VII), separable by column chromatography. The desired isomer (VII) is then reduced by LiAlH4 to alcohol (VIII), which is further protected as the silyl ether (IX). Debenzylation of (IX) by transfer hydrogenolysis with ammonium formate and Pearlman's catalyst furnishes pyrrolidine (X).