{4-[((S)-2-Amino-propionyl)-cyclopropyl-amino]-cyclohexyl}-carbamic acid tert-butyl ester

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

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

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

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

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

3-{[((S)-2-Amino-3-methyl-butyryl)-isopropyl-amino]-methyl}-piperidine-1-carboxylic acid tert-butyl ester

3-{[((S)-2-Amino-3-methyl-butyryl)-cyclopropyl-amino]-methyl}-pyrrolidine-1-carboxylic acid tert-butyl ester

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

4-(Carboxymethyl-amino)-piperidine-1-carboxylic acid benzyl ester

(2-Benzyloxycarbonylamino-cyclohexylamino)-acetic acid

[(4-Benzyloxycarbonylamino-cyclohexyl)-ethyl-amino]-acetic acid

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

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

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