Conformational analysis of 2-oxo-1,2,3,4,-tetrahydropyridine and its alkyl- and phenyl-substituted derivatives

The molecular geometries and inversion barriers of the rings in 2-oxo-1,2,3,4-tetrahydropyridine and its alkyl-substituted (Me, Et, Prⁱ, or Bu^t) and phenyl-substituted derivatives were calculated by the molecular mechanics method. The introduction of substituents has no substantial effect on the equilibrium conformation of the heterocycle (a distorted sofa). For 4-alkyl- and 3-alkyl-substituted derivatives (except for 4-Me and 4-Et derivatives), an axial orientation of the alkyl group is more favorable. The phenyl substituents have equatorial and axial orientations at postions 4 and 3, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1584–1586, September, 1997.