Hydrogen-bonding pattern of a beta-keto acid: (+/-)-10-oxo-3,4-benzobicyclo[4.3.1]dec-3-ene-1-carboxylic acid

In the title compound, C15H16O3, enantiomeric pairs of molecules form centrosymmetric dimers by mutual hydrogen bonding of carboxy groups, with the ketone not involved in the hydrogen bonding. The plane of the carboxy group [O(2)-C(11)-O(3)] makes a dihedral angle of 86.3 (2)degrees with the plane of the ketone {O(1)-C(1O)[-C(1)]-C(6)}. The observed C-O bond lengths and angles in the carboxy group are equivalent due to disorder. There is a reciprocal intermolecular 2.570(4)Angstrom contact between an aromatic H atom [H(14A)] and the ketone O atom [O(1)].