3-{5-[3-Eth-(E)-ylidene-4-methyl-5-oxo-pyrrolidin-(2Z)-ylidenemethyl]-4-methyl-1H-pyrrol-3-yl}-propionic acid allyl ester

3-(2-Allyloxycarbonyl-ethyl)-4-methyl-5-{4-methyl-5-oxo-3-[1-(toluene-4-sulfonyl)-ethyl]-4,5-dihydro-1H-pyrrol-2-ylmethyl}-1H-pyrrole-2-carboxylic acid tert-butyl ester