Showing structure for methyl 12-(acetyloxy)-16-(furan-3-yl)-4,9,9,15-tetramethyl-5,10,18-trioxo-2,6,17-trioxapentacyclo[10.7.0.0¹,¹⁵.0³,¹¹.0⁴,⁸]nonadecane-7-carboxylate