(2S,4S)-4-Allyl-5-hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

(2R,6S)-2-amino-6-((R)-4-((S)-2-aminopropanamido)-4-carboxybutanamido)heptanedioic acid

(2R,4S)-2-((3aR,6R,7R,7aR)-7-Benzyloxy-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyran-6-ylmethyl)-4-tert-butoxycarbonylamino-pentanedioic acid dimethyl ester

(2S,4S,5S)-4,5-diallyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

1-tert-butyl 2-methyl (2S,4S)-4-propyl-1,2-pyrrolidinedicarboxylate