(5S)-5-(2-methylpropyl)-3-[(2E,6R,8E,10E,12E)-6,8,10,12-tetramethyltetradeca-2,8,10,12-tetraenoyl]-2,5-dihydro-1H-pyrrol-2-one = (5S)-3-[(1S,2R,4aR,6R,8aS)-2-(but-2-en-2-yl)-3,4a,6-trimethyl-1,2,4a,5,6,7,8,8a-octahydronaphthalene-1-carbonyl]-5-(2-methylpropyl)-2,5-dihydro-1H-pyrrol-2-one — reaction