Diethyl 1,8-diphenyl-11-oxatricyclo­[6.2.1.0^2,7]undeca-2,4,6-triene-9,10-dicarboxyl­ate

The title compound, C₂₈H₂₆O₅, is the Diels–Alder adduct from 1,3-diphenyl­benzo[c]furan and diethyl maleate. The mol­ecule comprises of a fused tricyclic system containing two five-membered rings, which are in envelope conformations with the O atom at the flap, and a six-membered ring adopting a boat conformation. The dihedral angle between phenyl substituents in the 1,8-positions is 55.1 (1)°. The ethyl groups are disordered over two sets of sites, with occupancy ratios of 0.648 (9):0.352 (9) and 0.816 (1):0.184 (1). In the crystal, pairs of C—H...π inter­actions link the mol­ecules into inversion dimers.