2-(tert-Butoxycarbonyl)octahydro-2H-pyrido[1,2-a]pyrazine-8-carboxylic acid

3-[({1-[benzyl(methyl)amino]cyclobutyl}methyl)carbamoyl]-3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)propanoic acid

3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-({spiro[2.4]heptan-1-yl}carbamoyl)propanoic acid

4-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-({spiro[2.5]octan-1-yl}carbamoyl)butanoic acid

4-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-[(3-hydroxybutan-2-yl)carbamoyl]butanoic acid

3-[(3-bromo-5-fluorophenyl)carbamoyl]-3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)propanoic acid

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

1-[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanamido]cyclopentane-1-carboxylic acid

1-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-methylbutanoyl]pyrrolidine-3-carboxylic acid

3-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)hexanamido]-2-methylpropanoic acid

2-{1-[(2S)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)hexanoyl]piperidin-4-yl}acetic acid