[(R)-1-((S)-2-Amino-propionyl)-piperidin-3-yl]-cyclopropyl-carbamic acid tert-butyl ester

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

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

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

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

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

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

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

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

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

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