Showing structure for (3s,4as,5r,6r,6ar,10r,10as,10br)-6,10-bis(acetyloxy)-3-ethenyl-10b-hydroxy-3,4a,7,7,10a-pentamethyl-1-oxo-hexahydro-2h-naphtho[2,1-b]pyran-5-yl acetate