4-methyl-1,2,4-oxadiazolidine-3,5-dione

ethyl (N-tert-butoxycarbonyl-L-phenylalanyl)glycinate

ethyl 2-(2-bromopropanoylamino)acetate

4-氨基-5-(羧甲基氨基)-5-氧代-戊酸

ethyl 2-[[4-methyl-2-(phenylmethoxycarbonylamino)pentanoyl]amino]acetate