(1R,4aS,7E,9R,11aR)-4-[(1R,2R)-1,2-Diacetoxy-4-methyl-3-pentenyl]-1,4a,5,6,9,10,11,11a-octahydro-7-methyl-11-methylenecyclonona[c]pyran-1,9-diol diacetate