Showing structure for methyl (2s,4s,6r,9e,12s,18s)-18-(acetyloxy)-4-methyl-8-oxo-12-(prop-1-en-2-yl)-3,7,17-trioxatetracyclo[12.2.1.1⁶,⁹.0²,⁴]octadeca-1(16),9,14-triene-15-carboxylate