Showing structure for 11-hydroxy-4,5,19-trimethoxy-9,10-dimethyl-15,17-dioxatetracyclo[10.7.0.0²,⁷.0¹⁴,¹⁸]nonadeca-1(12),2(7),3,5,13,18-hexaen-3-yl 2-methylbut-2-enoate