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

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

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

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

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

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

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

((S)-3-tert-Butoxycarbonylamino-pyrrolidin-1-yl)-acetic acid

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