3,3-Dimethyl-4-nitrobutanoic acid

2-(1-{[4-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2,2-dimethylbutanamido]methyl}cyclobutyl)acetic acid

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

2-({2-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-5-methoxypentanamido]ethyl}sulfanyl)acetic acid

5-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-methoxypropanamido]pentanoic acid

4-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-methoxypropanamido]pentanoic acid

3-[(2S)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-methylbutanamido]-2,2-dimethylpropanoic acid

1-{[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanamido]methyl}cyclobutane-1-carboxylic acid

2-[(2-{[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)cyclopentyl]formamido}ethyl)sulfanyl]acetic acid

2-({2-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3,3,3-trifluoro-2-methylpropanamido]ethyl}sulfanyl)acetic acid

2-[(2-{[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-methyl-1,3-thiazol-5-yl]formamido}ethyl)sulfanyl]acetic acid