Showing structure for 2-(acetyloxy)-7-formyl-11-hydroxy-11-methyl-16-oxo-4-(prop-1-en-2-yl)-15,17,18-trioxatetracyclo[11.2.2.1⁶,⁹.0¹,¹⁴]octadeca-6,8-dien-10-yl acetate