4-[((S)-2-Amino-propionyl)-cyclopropyl-amino]-piperidine-1-carboxylic acid tert-butyl ester

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

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

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

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

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

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

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

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

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

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

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

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

(1R,4R)-(4-Benzyloxycarbonylamino-cyclohexylamino)-acetic acid

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