(2R)-4-(2-aminoethyl)-2-methyl-1lambda6-thiomorpholine-1,1-dione dihydrochloride

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

(2R)-4-(but-3-yn-1-yl)-2-methylthiomorpholine

(2R)-4-(dimethylamino)butan-2-ol

(2R)-4-(dimethylamino)butan-2-ol hydrochloride

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

(2R)-4-(methylamino)butan-2-ol

(2R)-4-(piperidin-4-yl)butan-2-ol hydrochloride

(2R)-4-(pyridin-4-yl)but-3-yn-2-ol

(2R)-4-(pyridin-4-yl)butan-2-ol

(2R)-4-(tert-butoxy)-2-(dimethylamino)-4-oxobutanoic acid

(2R)-4-(tert-butoxy)-2-hydroxy-4-oxobutanoic acid

(2R)-4-(tert-butoxy)-2-{[(tert-butoxy)carbonyl]amino}-4-oxobutanoic acid

(2R)-4-(tert-butoxy)butan-2-amine hydrochloride

(2R)-4-(tetramethyl-1,3,2-dioxaborolan-2-yl)but-3-en-2-ol

(2R)-4-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-hydroxybutanoic acid

(2R)-4-amino-1-(benzyloxy)butan-2-ol hydrochloride

(2R)-4-amino-2-hydroxybutanoic acid hydrochloride

(2R)-4-amino-2-methoxybutanoic acid hydrochloride

(2R)-4-amino-2-{[(tert-butoxy)carbonyl]amino}butanoic acid

(2R)-4-aminobutan-2-ol

(2R)-4-aminobutane-1,2-diol hydrochloride

(2R)-4-bromobutan-2-amine hydrobromide

(2R)-4-carbamoyl-2-(dimethylamino)butanoic acid

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

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

(2R)-4-carbamoyl-2-decanamidobutanoic acid

(2R)-4-carbamoyl-2-[(2S)-2-(methylamino)propanamido]butanoic acid

(2R)-4-chlorobutan-2-amine hydrochloride

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

(2R)-4-ethoxy-2-methyl-4-oxobutanoic acid

(2R)-4-ethoxybutan-2-amine hydrochloride

(2R)-4-fluorobutan-2-amine hydrochloride

(2R)-4-fluorobutan-2-ol

(2R)-4-fluorobutane-1,2-diol

(2R)-4-hydroxy-2-(methylamino)butanoic acid hydrochloride

(2R)-4-methoxybutan-2-amine hydrochloride

(2R)-4-methyl-2-(1-oxo-2,3-dihydro-1H-isoindol-2-yl)pentanoic acid

(2R)-4-methyl-2-(methylamino)pentan-1-ol

(2R)-4-methylpentan-2-amine hydrochloride

(2R)-4-methylpiperazine-2-carboxylic acid dihydrochloride

(2R)-4-oxoazetidine-2-carboxylic acid

(2R)-4-phenoxybutan-2-amine hydrochloride

(2R)-4-phenylbutan-2-amine hydrochloride

(2R)-4-phenylbutan-2-ol