(S)-3-((S)-2-Amino-3-methyl-butyrylamino)-piperidine-1-carboxylic acid tert-butyl ester

(R)-3-[((S)-2-Amino-3-methyl-butyryl)-cyclopropyl-amino]-piperidine-1-carboxylic acid tert-butyl ester

(R)-3-(Carboxymethyl-amino)-piperidine-1-carboxylic acid benzyl ester

(R)-3-(Carboxymethyl-ethyl-amino)-piperidine-1-carboxylic acid benzyl ester

2-[(Carboxymethyl-isopropyl-amino)-methyl]-pyrrolidine-1-carboxylic acid benzyl ester

3-[(Carboxymethyl-isopropyl-amino)-methyl]-piperidine-1-carboxylic acid benzyl ester

(R)-3-(Carboxymethyl-cyclopropyl-amino)-pyrrolidine-1-carboxylic acid benzyl ester

(1R,4R)-[(4-Benzyloxycarbonylamino-cyclohexyl)-cyclopropyl-amino]-acetic acid

2-{[(2-Hydroxy-ethyl)-methyl-amino]-methyl}-piperidine-1-carboxylic acid benzyl ester

3-{[Ethyl-(2-hydroxy-ethyl)-amino]-methyl}-pyrrolidine-1-carboxylic acid benzyl ester

(S)-3-[(2-Hydroxy-ethyl)-isopropyl-amino]-pyrrolidine-1-carboxylic acid benzyl ester