methyl 2-((1R,2S,3S,3aS,3bS,7aS,8R,8aR)-1-hydroxy-7a-methyl-2-((Z)-pent-2-en-1-yl)-8-phenyl-2,3,3a,4,5,6,7,7a,8,8a-decahydro-1H-3b,8-ethenocyclopenta[a]inden-3-yl)acetate