Showing structure for methyl 3-[17,18-bis(acetyloxy)-7-(furan-3-yl)-1,8,15,15-tetramethyl-5-oxo-3,6,14-trioxapentacyclo[9.7.0.0²,⁴.0²,⁸.0¹²,¹⁶]octadecan-12-yl]prop-2-enoate