7-methyl-8-((E)-2-((1S,3aR,7aS)-7a-methyl-1-(2-methyl-1,3-dioxolan-2-yl)-2,3,3a,6,7,7a-hexahydro-1H-inden-4-yl)vinyl)-1,4-dioxaspiro[4.5]dec-7-ene