One molecule can make a difference.

Benzyl (2S)-2-{[(tert-butoxy)carbonyl]amino}hex-5-ynoate

N-(tert-butoxycarbonyl)-O-methyl-L-homoserine

MW 233.13

methyl (S)-3-(3-(benzyloxy)-2-((tert-butoxycarbonyl)amino)-3-oxopropyl)benzoate

MW 413.18

benzyl (S)-3-(5-bromopyridin-2-yl)-2-((tert-butoxycarbonyl)amino)propanoate

MW 434.08

methyl (S)-4-(3-(benzyloxy)-2-((tert-butoxycarbonyl)amino)-3-oxopropyl)benzoate

MW 413.18

(R)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-4-aminobutanoic acid

MW 340.14

methyl (S)-2-acetamido-3-(4-acetylphenyl)propanoate

MW 263.12

N-(((tert-butyldimethylsilyl)oxy)methyl)-4-methylbenzenesulfonohydrazide

MW 330.14