Showing structure for 18-(furan-3-yl)-8,8,12,19-tetramethyl-6,16-dioxo-7,14,17-trioxapentacyclo[10.9.0.0²,⁹.0¹³,¹⁵.0¹³,¹⁹]henicosa-1(21),4-dien-11-yl acetate