1-[[(4-Phenylmethyl-1-piperazinyl)carbonyl]amino]cyclohexanecarboxylic acid ethyl ester

4-[3-(benzyloxy)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanamido]-3-chlorobenzoic acid

3-[3-(benzyloxy)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanamido]-4-chlorobenzoic acid

2-[(2R,3S)-3-(benzyloxy)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanamido]-3,3,3-trifluoro-2-methylpropanoic acid

1-[(2R,3S)-3-(benzyloxy)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanoyl]-2-methylpiperidine-4-carboxylic acid

3-[(2R)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)pentanamido]oxolane-2-carboxylic acid

5-({[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)oxolan-2-yl]formamido}methyl)furan-2-carboxylic acid

2-{4-[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)oxolane-2-amido]-1H-pyrazol-1-yl}acetic acid

1-[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)oxolane-2-carbonyl]-5-hydroxypiperidine-3-carboxylic acid

rac-4-[(2R,3S)-3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)oxolane-2-amido]oxolane-3-carboxylic acid

rac-(2R,3S)-3-{2-[1-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)cyclopentyl]acetamido}oxolane-2-carboxylic acid