3-Penten-1-one,1-[1,7-bis(acetyloxy)-1,4a,5,6,7,10,11,11a-octahydro-7-methyl-11-methylenecyclonona[c]pyran-4-yl]-4-methyl-,(1R*,4aR*,7R*,8E,11aS*)-(-)-