Showing structure for methyl 2-[10,13-bis(acetyloxy)-1,14-dihydroxy-4,15-dimethyl-8-oxo-3,7,17-trioxatetracyclo[12.2.1.1⁶,⁹.0²,⁴]octadeca-9(18),15-dien-12-yl]prop-2-enoate