Showing structure for 10-acetyl-21-hydroxy-6,6,17,17-tetramethyl-7,12,18-trioxapentacyclo[11.8.0.0³,¹¹.0⁵,⁹.0¹⁴,¹⁹]henicosa-1(21),3(11),13,15,19-pentaene-2,8-dione