(2S,5R,6S)-6-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid

3-methyl-2-(5-phthalimido-6-oxo-6H-[1,3]thiazin-3-yl)-but-2-enoic acid methyl ester

methyl (S,E)-3-(2-(1,3-dioxoisoindolin-2-yl)-3-methoxy-3-oxoprop-1-en-1-yl)-5,5-dimethylthiazolidine-4-carboxylate