3-(2-Amino-ethylsulfanyl)-piperidine-1-carboxylic acid tert-butyl ester

(S)-3-(Carboxymethyl-ethyl-amino)-piperidine-1-carboxylic acid tert-butyl ester

[(4-tert-Butoxycarbonylamino-cyclohexyl)-ethyl-amino]-acetic acid

[(4-tert-Butoxycarbonylamino-cyclohexyl)-isopropyl-amino]-acetic acid

2-(((1R,4R)-4-((tert-butoxycarbonyl)amino)cyclohexyl)-(cyclopropyl)amino)acetic acid

(S)-3-(2-Chloro-acetylamino)-piperidine-1-carboxylic acid tert-butyl ester

(1R,4R)-[4-(2-Chloro-acetylamino)-cyclohexyl]-carbamic acid tert-butyl ester

3-{[(2-Chloro-acetyl)-methyl-amino]-methyl}-piperidine-1-carboxylic acid tert-butyl ester

3-[(2-Chloro-acetyl)-ethyl-amino]-piperidine-1-carboxylic acid tert-butyl ester

4-{[(2-Chloro-acetyl)-ethyl-amino]-methyl}-piperidine-1-carboxylic acid tert-butyl ester

(S)-3-[(2-Chloro-acetyl)-isopropyl-amino]-piperidine-1-carboxylic acid tert-butyl ester