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

[(S)-1-((S)-2-Amino-3-methyl-butyryl)-pyrrolidin-3-yl]-carbamic acid tert-butyl ester

(1R,4R)-[4-((S)-2-Amino-3-methyl-butyrylamino)-cyclohexyl]-carbamic acid tert-butyl ester

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

[1-((S)-2-Amino-3-methyl-butyryl)-piperidin-3-yl]-ethyl-carbamic acid tert-butyl ester

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

[1-((S)-2-Amino-3-methyl-butyryl)-piperidin-3-yl]-isopropyl-carbamic acid tert-butyl ester

[1-((S)-2-Amino-3-methyl-butyryl)-pyrrolidin-3-ylmethyl]-cyclopropyl-carbamic acid tert-butyl ester

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

[(S)-3-(tert-Butoxycarbonyl-methyl-amino)-piperidin-1-yl]-acetic acid

[4-(tert-Butoxycarbonyl-methyl-amino)-cyclohexylamino]-acetic acid