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

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

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

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

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

[1-((S)-2-Amino-3-methyl-butyryl)-piperidin-4-ylmethyl]-methyl-carbamic acid tert-butyl ester

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

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

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

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

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

(3-tert-Butoxycarbonylamino-piperidin-1-yl)-acetic acid

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

{2-[(tert-Butoxycarbonyl-methyl-amino)-methyl]-piperidin-1-yl}-acetic acid

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