3-[(2-Amino-acetyl)-cyclopropyl-amino]-pyrrolidine-1-carboxylic acid tert-butyl ester

(1R,4R)-[4-((S)-2-Amino-propionylamino)-cyclohexyl]-carbamic acid tert-butyl ester

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

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

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

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

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

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

[4-((S)-2-Amino-3-methyl-butyrylamino)-cyclohexyl]-carbamic acid tert-butyl ester

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

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