{4-[(2-Amino-acetyl)-isopropyl-amino]-cyclohexyl}-carbamic acid tert-butyl ester

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

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

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

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

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

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

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

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

{4-[((S)-2-Amino-3-methyl-butyryl)-isopropyl-amino]-cyclohexyl}-carbamic acid tert-butyl ester

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