Synthesis, crystal structure and DFT studies of 3,4-bis-(2-chloro-phenyl)-2-oxa-bicyclo [2.2.1] heptan-6-one

A bicyclic 3,4-bis-(2-chloro-phenyl)-2-oxa-bicyclo[2.2.1]heptan-6-one (3) was synthesized and characterized by single-crystal X-ray analysis. The compound crystallizes in orthorhombic system, space group Pna21, with a = 18.813(3) Å, b = 11.198(2) Å, c = 7.1985(13) Å, V = 1516.5(5) Å3, Z = 4. The lactone ring in (3) adopts a boat conformation and is folded about the bridgehead CC bond by 109.5(1)°. The crystal packing of (3) exhibits intermolecular CH⋯O hydrogen bonds forming C(8) and C(4) chains propagating parallel to the [0 1 0] and [0 0 1] directions, respectively, which are further linked via CH⋯π (arene) hydrogen bonds to generate a three dimensional network. The molecular geometries and electronic structure of (3) were calculated at the DFT level using the hybrid exchange-correlation functional, BLYP. The HOMO–LUMO gap in (3) (4.15 eV) indicates a high kinetic stability of the title compound.