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

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

((S)-3-Benzyloxycarbonylamino-pyrrolidin-1-yl)-acetic acid

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

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

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

{2-[(Benzyloxycarbonyl-ethyl-amino)-methyl]-pyrrolidin-1-yl}-acetic acid

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

{4-[(Benzyloxycarbonyl-ethyl-amino)-methyl]-piperidin-1-yl}-acetic acid

(1R,4R)-[4-(Benzyloxycarbonyl-ethyl-amino)-cyclohexylamino]-acetic acid

(1R,4R)-[4-(Benzyloxycarbonyl-isopropyl-amino)-cyclohexylamino]-acetic acid