(S)-3-{2-[2-(tert-Butyl-dimethyl-silanyloxymethyl)-pyridin-3-yl]-ethyl}-4-vinyl-oxazolidin-2-one

2-{(S)-3-[2-(2-Formyl-pyridin-3-yl)-ethyl]-2-oxo-oxazolidin-4-ylmethylene}-malonic acid di-tert-butyl ester

dimethyl (2S,3R,4S)-3-(1,3-di-tert-butoxy-1,3-dioxopropan-2-yl)-4-(2-(methoxycarbonyl)pyridin-3-yl)pyrrolidine-1,2-dicarboxylate