4-Ethyl-5-[1-(4-ethyl-3-methyl-5-methylene-5H-pyrrol-2-yl)-meth-(Z)-ylidene]-3-methyl-1,5-dihydro-pyrrol-2-one

5-<5-(5-tert-Butoxycarbonyl-4-ethyl-3-methyl-2H-pyrrolidenmethyl)-4-ethyl-3-methyl-2-pyrrolylmethylen>-4-ethyl-3-methyl-3-pyrrolin-2-on