organic compounds
Open access
In the title compound, C33H38N4O3, the mean planes of the 9H-xanthene unit and spirolactam (nine-atom) core are almost mutually perpendicular at 87.26 (6)°. Intramolecular N—HO and C—HN interactions influence the 4-oxopent-2-en-2-ylamino conformation. In the crystal, weak C—HO hydrogen bonds link the molecules into chains along [001].