Showing structure for (1r,13r,16s,18r)-3-hydroxy-13,17,17-trimethyl-8,12-dioxapentacyclo[11.4.1.0²,¹¹.0⁴,⁹.0¹⁶,¹⁸]octadeca-2(11),3,5,9-tetraen-7-one