合成路线1

The condensation of 2-pyrrolidinone (I) with 2-oxoacetic acid (II) in ethyl ether gives 2-hydroxy-2-(2-oxopyrrolidin-1-yl)acetic acid (III), which is fully methylated with methanol and conc. sulfuric acid to yield 2-methoxy-2-(2-oxopyrrolidin-1-yl)acetic acid methyl ester (IV). The reaction of (IV) with PCl3 in hot toluene affords 2-chloro-2-(2-oxopyrrolidin-1-yl)acetic acid methyl ester (V), which is condensed with triethyl phosphite (VI), also in hot toluene, to provide the dimethyl phosphonate (VII). The condensation of (VII) with acetaldehyde (VIII) in THF by means of tetramethylguanidine gives 2-(2-oxopyrrolidin-1-yl)-2-butenoic acid methyl ester (IX), which is reduced with H2 and a chiral Rhodium catalyst in THF to yield 2(S)-(2-oxopyrrolidin-1-yl)butyric acid methyl ester (X). Finally, this ester is treated with ammonia in methanol to afford the target chiral amide.