Crystal structure and Hirshfeld surface analysis of dieth-yl (3a S ,3 a 1 R ,4 S ,5 S ,6 R ,6a S ,7 R ,9a S )-3a1,5,6,6a-tetra-hydro-1 H ,3 H ,4 H ,7 H -3a,6:7,9a-di-epoxy-benzo[ de ]isochromene-4,5-di-carboxyl-ate.

In the title compound, C 18 H 22 O 7 , two hexane rings and an oxane ring are fused together. The two hexane rings tend toward a distorted boat conformation, while the tetra-hydro-furan and di-hydro-furan rings adopt envelope conformations. The oxane ring is puckered. The crystal structure features C-H⋯O hydrogen bonds, which link the mol-ecules into a three-dimensional network. According to a Hirshfeld surface study, H⋯H (60.3%) and O⋯H/H⋯O (35.3%) inter-actions are the most significant contributors to the crystal packing.