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

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

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

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

4-ethylidene-3,3-dimethyl-5-thioxo-pyrrolidin-2-one