Showing structure for (3ar,4s,5ar,6s,9s,9as,9bs)-5a-methyl-4-{[(2z)-2-methylbut-2-enoyl]oxy}-3-methylidene-2-oxo-octahydrospiro[naphtho[1,2-b]furan-9,2'-oxiran]-6-yl (2z)-2-(hydroxymethyl)but-2-enoate