(S)-7-(Benzyloxy-formyl-amino)-2-[(1-{(2S,3S)-2-[(R)-2-tert-butoxycarbonylamino-3-(4-methoxy-phenyl)-propionylamino]-3-methyl-pentanoyl}-piperidine-2-carbonyl)-amino]-heptanoic acid

(S)-7-(Benzyloxy-formyl-amino)-2-tert-butoxycarbonylamino-heptanoic acid 2-trimethylsilanyl-ethyl ester

(S)-2-Amino-7-(benzyloxy-formyl-amino)-heptanoic acid

(S)-7-(Benzyloxy-formyl-amino)-2-tert-butoxycarbonylamino-heptanoic acid

(S)-2-Amino-7-(benzyloxy-formyl-amino)-heptanoic acid 2-trimethylsilanyl-ethyl ester