The title compound, C16H20O3, was prepared by the photolysis of 7-hydroxy-2-methyl-2-(4-methyl-3-pentenyl)-4-chromanone. The H7 and H9 atoms are in an [alpha] configuration. The cyclobutane ring is non-planar, the cyclohexenone ring has a half-chair conformation, the pyranone ring has a sofa conformation and the cycloheptanone ring has a boat conformation. The groups of atoms C11, C12, C13, O14 and C12, C13, O14, C4 are both planar.
V. Kabaleeswaran, Rajan, S. S., Kalena, G. P., Pradhan, P., and Banerji, A., “(1alpha$, 3alpha$, 11alpha)-2, 2, 11-Trimethyl-14-oxatetracyclo [6.5. 0.17, 11.03, 8] tetradec-6-ene-5, 9-dione”, Acta Crystallographica Section C: Crystal Structure Communications, vol. 52, pp. 1981–1983, 1996.