Methyl (S)-2-hydroxy-2-(4-nitrophenyl)acetate

((S)-5-Acetylamino-5-{4-[(2-{2-[2-(9H-fluoren-9-ylmethoxycarbonylamino)-ethoxy]-ethoxy}-ethylcarbamoyl)-hydroxy-methyl]-phenylcarbamoyl}-pentyl)-carbamic acid tert-butyl ester

4-nitromandelic acid methyl ester acetate

{4-[acetyl-Lys(Boc)amino]-phenyl}-hydroxy-acetic acid methyl ester

[4-((S)-2-Acetylamino-6-tert-butoxycarbonylamino-hexanoylamino)-phenyl]-hydroxy-acetic acid