Showing structure for (1r,3r,4s,6s,8s,9r,10s,11s)-10-[(2e)-but-2-enoyloxy]-8-hydroxy-3,8-dimethyl-12-methylidene-7,13-dioxo-5,14-dioxatricyclo[9.3.0.0⁴,⁶]tetradecan-9-yl (2e)-but-2-enoate