2-Butenoic acid, 2-methyl-,(4S,6R,7S,10R,11E)-2,4,5,6,7,8,9,10-octahydro-7-hydroxy-3-(hydroxymethyl)-6,10-dimethyl-2-oxo-7,10-epoxycyclodeca[b]furan-4-yl ester,(2E)-