4-(9-Anthr­yl)-1-(2-methoxy­phen­yl)spiro­[azetidin-3,9′-xanthen]-2-one

The stabilized conformation of the title compound, C(36)H(25)NO(3), 4-(9-anthryl)-1-(2-methoxyphenyl)-spiro[azetid­in-3,9′-xanthen]-2-one, may be compared with that of the isomeric compound 4-(9-anthr­yl)-1-(4-methoxy­phen­yl)spiro­[azetidin-3,9′-xanthen]-2-one. In the title isomer, the meth­oxy group is slightly twisted out of the plane of the attached benzene ring, with a C—O—C—C torsion angle of 31.5 (2)°. Its β-lactam ring is essentially planar, with a maximum deviation of −0.021 (1) Å. The β-lactam ring makes dihedral angles of 18.815 (9), 83.33 (7) and 53.62 (8)° with the mean planes of the benzene, xanthene and anthracene ring systems, respectively. The structure is stabilized by C—H⋯π, C—H⋯N and C—H⋯O inter­actions.