Showing structure for methyl (1r,4as,5r,6r,8s,8ar)-5-{3-[(3r,4as,7ar)-7a-methyl-6-oxo-tetrahydrofuro[3,2-c][1,2]dioxin-3-yl]but-3-en-1-yl}-6,8-dihydroxy-1,4a,6-trimethyl-hexahydro-2h-naphthalene-1-carboxylate