1,1-Dimethoxyhexane-2,4-dione

(2S)-2-{[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-1,3-thiazol-4-yl]formamido}-4-(methylsulfanyl)butanoic acid

2-{4-[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanoyl]-1,4-diazepan-1-yl}acetic acid

2-[N-ethyl-5-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)hexanamido]-2-methylpropanoic acid

5-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-methoxybutanamido]hexanoic acid

3-{[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-methylphenyl]formamido}butanoic acid

3-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-(thiophen-2-yl)acetamido]-3-methylbutanoic acid

4-[1-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)cyclopentanecarbonyl]thiomorpholine-3-carboxylic acid

1-[5-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)hexanoyl]piperidine-3-carboxylic acid

2-{1-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-1,3-thiazol-4-yl]-N-methylformamido}acetic acid

(2S)-3-[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)pentanamido]-2-hydroxypropanoic acid