(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 = (3Z)-3-[(2E,6R,8E,10E,12E)-1-hydroxy-6,8,10,12-tetramethyltetradeca-2,8,10,12-tetraen-1-ylidene]-5-(2-methylpropyl)-2,3-dihydro-1H-pyrrol-2-one — reaction