[1-((S)-2-Amino-propionyl)-piperidin-4-yl]-carbamic acid benzyl ester

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

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

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

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

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

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

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

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

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

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