Showing structure for (1r,2r,4r,6r,9z,11r)-4-methyl-2-{[(2e)-2-methylbut-2-enoyl]oxy}-14-methylidene-13-oxo-5,12-dioxatricyclo[9.3.0.0⁴,⁶]tetradec-9-ene-9-carboxylic acid