Showing structure for (13r)-8,17-dihydroxy-6,19-dimethoxy-14,14-dimethyl-3,15-dioxapentacyclo[11.6.1.0²,¹¹.0⁴,⁹.0¹⁶,²⁰]icosa-1(19),2(11),4,6,8,16(20),17-heptaen-10-one