3-{5-[allyloxycarbonyl-(4-methyl-5-oxo-3-propylidene-pyrrolidin-2-ylidene)-methyl]-2-formyl-4-methyl-1H-pyrrol-3-yl}-propionic acid allyl ester

3-methyl-4-propylidene-pyrrolidine-2,5-dione

3-methyl-4-propylidene-5-thioxo-pyrrolidin-2-one

3-(2-allyloxycarbonyl-ethyl)-5-[allyloxycarbonyl-(4-methyl-5-oxo-3-propylidene-pyrrolidin-2-ylidene)-methyl]-4-methyl-1H-pyrrole-2-carboxylic acid tert-butyl ester