tert-butyl [(3R,4R,5S)-4-{[tert-butyl(dimethyl)silyl]oxy}-5-methyl-1-(3-nitropyridin-4-yl)piperidin-3-yl]carbamate

tert-butyl ((3R,4R,5S)-1-(3-aminopyridin-4-yl)-4-{[tert-butyl(dimethyl)silyl]oxy}-5-methylpiperidin-3-yl)carbamate

tert-butyl (4R)-4-((1R,2R)-3-[(4R)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]-1-{[tert-butyl(dimethyl)silyl]oxy}-2-methyl-3-oxopropyl)-2,2-dimethyl-1,3-oxazolidine-3-carboxylate