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 carboxyl groups, with the ketone not involved in the hydrogen bonding. The plane of the carboxyl group [O(2)-C(11)-O(3)] makes a dihedral angle of 86.3 (2)° with the plane of the ketone {O(1)-C(10)[-C(1)-C(6)]}. The observed C-O bond lengths and angles in the carboxyl group are equivalent due to disorder. There is a reciprocal intermolecular 2.570 (4) Å contact between the aromatic H(14 A) and the ketone O atom [O(1)].

-1