Acanthospermolide

2-Methylpropanoic acid [(3aS,4S,5S,6E,10E,11aR)-6-formyl-2,3,3a,4,5,8,9,11a-octahydro-5-methoxy-10-methyl-3-methylene-2-oxocyclodeca[b]furan-4-yl] ester