4-Tosyl-1-oxa-4-azaspiro[4.5]deca-6,9-dien-8-one

In the molecule of the title compound, C15H15NO4S, the two six-membered rings are almost parallel to each other [dihedral angle = 1.87 (9)°] and perpendicular to the mean plane through the five-membered ring [dihedral angles of 89.98 (10) and 89.04 (10)°]. The crystal structure is stabilized by intermolecular C—H⋯O hydrogen-bonding interactions.