(2S,3R)-3-(Benzyloxycarbonyl-methyl-amino)-2-methanesulfonyloxy-butyric acid methyl ester

(2R,3R)-3-[(9H-Fluoren-9-ylmethoxycarbonyl)-methyl-amino]-2-(4-methyl-benzyloxycarbonylamino)-butyric acid methyl ester

(2S,4R)-2-{[(1R,2R)-2-Carboxy-1-methyl-2-(4-methyl-benzyloxycarbonylamino)-ethyl]-methyl-carbamoyl}-4-((Z)-propenyl)-pyrrolidine-1-carboxylic acid tert-butyl ester

(2S,4R)-2-{[(1R,2R)-2-Methoxycarbonyl-1-methyl-2-(4-methyl-benzyloxycarbonylamino)-ethyl]-methyl-carbamoyl}-4-((Z)-propenyl)-pyrrolidine-1-carboxylic acid tert-butyl ester

[5-sec-butyl-18,19-dimethyl-11-(2-nitro-cyclopropylmethyl)-4,7,10,13,16,20-hexaoxo-8,14-bis-(1-phenyl-ethyl)-2-propenyl-eicosahydro-3a,6,9,12,15,19-hexaaza-cyclopentacyclononadecen-17-yl]-carbamic acid 4-methyl-benzyl ester

(2R,3R)-3-Methylamino-2-(4-methyl-benzyloxycarbonylamino)-butyric acid methyl ester

methyl (2S,3R)-2-azido-3-(benzyloxycarbonyl-N-methylamino)butyrate

(2R,3R)-2-tert-Butoxycarbonylamino-3-methylamino-butyric acid methyl ester

(2R,3R)-3-(Benzyloxycarbonyl-methyl-amino)-2-tert-butoxycarbonylamino-butyric acid methyl ester

(2R,3R)-2-tert-Butoxycarbonylamino-3-[(9H-fluoren-9-ylmethoxycarbonyl)-methyl-amino]-butyric acid methyl ester