2-(4-(2-ethylphenyl)-2,3-dioxo-3,4-dihydropyrazin-1(2H)-yl)acetonitrile

rac-(3R,4R)-1-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-methyl-1,3-thiazole-5-carbonyl]-4-methylpyrrolidine-3-carboxylic acid

(2R)-1-[(2S)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-phenylacetyl]pyrrolidine-2-carboxylic acid

(2S)-2-{[6-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)pyridin-2-yl]formamido}-4-hydroxybutanoic acid

2-{[6-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)pyridin-2-yl]formamido}butanoic acid

2-[5-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-methyl-N-propylpentanamido]acetic acid

5-[(2S)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-methylbutanamido]-2-methylpentanoic acid

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

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

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

2-[N-tert-butyl-3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-methylbutanamido]acetic acid