methyl (R)-2-((2-(1H-imidazol-1-yl)-5-nitropyrimidin-4-yl)(cyclopentyl)amino)butanoate

methyl O-((R)-3-methoxy-2-methyl-3-oxopropyl)-L-homoserinate

methyl (R)-2-((2-chloro-5-nitropyrimidin-4-yl)(3,3-difluorocyclobutyl)amino)butanoate