Molecular and crystal structure of 4,6,6-trimethyl-2-oxo-5,6-dihydro-2H- pyran-3-carbonitrile and 4,6,6-trimethyl-2-oxo-1,2,5,6-tetrahydropyridine-3- carbonitrile

Single crystals of 4,6,6-trimethyl-2-oxo-5,6-dihydro-2H-pyran-3- carbonitrile and 4,6,6-trimethyl-2-oxo-1,2,5,6-tetrahydropyridine-3-carbonitrile were prepared and submitted to X-ray diffraction analysis. Both compounds have a molecular structure belonging to the C1 symmetry group. The heterocyclic rings are in a distorted envelope conformation. The crystals belong to the monoclinic system and each contain four molecules in the unit cell. In the crystal the pyridine derivative exists in the form of centrosymmetric dimers stabilized by intermolecular hydrogen bonds between the oxygen atoms of the carbonyl group and the hydrogen atom at the nitrogen atom of the ring. © 2007 Springer Science+Business Media, Inc.