Showing structure for (1r,2s,3r,7s,8r)-6-ethenyl-11-methylidene-5,10-dioxo-7-(3-oxoprop-1-en-2-yl)-4,9-dioxatricyclo[6.3.0.0³,⁶]undecan-2-yl (2e)-2-methylbut-2-enoate