(2R,4R) diethyl-1-benzyl-4-(tert-butyloxycarbonylamino) pyrrolidine-2,4-dicarboxylate

(2R,4R)-1-benzyl-2-ethoxycarbonylpyrrolidine-4-spiro-5'-hydantoin

苄基氯

(2R,4R)-4-氨基-2,4-吡咯烷二甲酸

ethyl (5R,8R)-2,4-dioxo-1,3,7-triazaspiro[4.4]nonane-8-carboxylate