3-{5-[4-Ethyl-3-methyl-5-oxo-1,5-dihydro-pyrrol-(2Z)-ylidenemethyl]-4-methyl-1H-pyrrol-3-yl}-propionic acid allyl ester

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

3-ethyl-4-ethylidene-1-(4-methoxy-benzyl)-pyrrolidine-2,5-dione

3-ethyl-4-ethylidene-pyrrolidine-2,5-dione

3-ethyl-4-ethylidene-5-thioxo-pyrrolidin-2-one