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

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

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

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

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

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

[(R)-3-(tert-Butoxycarbonyl-ethyl-amino)-pyrrolidin-1-yl]-acetic acid

[4-(tert-Butoxycarbonyl-ethyl-amino)-piperidin-1-yl]-acetic acid

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

[(R)-3-(tert-Butoxycarbonyl-cyclopropyl-amino)-pyrrolidin-1-yl]-acetic acid

{3-[(tert-Butoxycarbonyl-cyclopropyl-amino)-methyl]-pyrrolidin-1-yl}-acetic acid