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

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

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

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

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

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

[2-(Benzyloxycarbonylamino-methyl)-pyrrolidin-1-yl]-acetic acid

[3-(Benzyloxycarbonyl-methyl-amino)-piperidin-1-yl]-acetic acid

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

[(S)-3-(Benzyloxycarbonyl-ethyl-amino)-pyrrolidin-1-yl]-acetic acid

[(R)-3-(Benzyloxycarbonyl-ethyl-amino)-piperidin-1-yl]-acetic acid