3-Mesityl-2-oxo-1-oxaspiro­[4.4]non-3-en-4-yl benzoate

In the title compound, C(24)H(24)O(4), a derivative of the potent insecticide and miticide spiro­mesifen, one cyclo­pentane C atom is disordered over two positions with occupancies of 0.574 (12) and 0.426 (12), resulting in respective envelope and twisted conformations for the cyclo­pentane ring. The atom at the flap position is 0.620 (5) Å out of the mean plane formed by the other four atoms of the envelope form. The furan ring makes dihedral angles of 68.26 (3) and 69.38 (2)°, respectively, with the 2,4,6-trimethyl­phenyl and benzene rings. The dihedral angle between the two benzene rings is 62.27 (3)°.