The title compound, C(40)H(40)O(9), is a product of the double crotonic condensation of bis-(2-acetyl-phen-oxy)-3-oxapentane with bis-(2-formyl-phen-oxy)-3,6-dioxaoctane. The title macromolecule includes the 31-crown-7-ether skeletal unit and adopts a saddle-like conformation. The two ethyl-ene fragments have E configurations. The volume of the inter-nal cavity of the macrocycle is approximately 125 Å(3). In the crystal, the mol-ecules are arranged at van der Waals distances.