Boc-(RS)Pheψ(COCH2)Gly-Leu-Met-NH2

6-phenyl-5-<(tert-butoxycarbonyl)amino>-4-oxohexanoic acid

δ-amino-γ-oxobenzenehexanoic acid hydrochloride

(R,S)-5-benzoylamino-4-oxo-6-phenylhexanoic acid methyl ester

Boc-pGlu-Phe-OH