Stereoelectronic interaction and their effects on conformational preference for 2-substituted methylenecyclohexane: an experimental and theoretical investigation.
Conformational preferences for 2-substituted methylenecyclohexanes were determined using (3) J H 2 H 3 spin-spin coupling constants, while stereoelectronic interactions were obtained by means of theoretical calculations and NBO analysis. The conformational equilibrium of compounds studied can be represented by their axial and equatorial conformers, the axial conformers being the most stable form in polar and nonpolar solvents. These conformational preferences were attributed to the hyperconjugative interactions between the pi C-C-->sigma* C-Xax. and sigma C-H-->sigma* C-Xax. orbitals, and the repulsive steric interaction observed between sigma C-H-->n Xeq..
Anizelli
Pedro R
PR
Department of Organic Chemistry, Chemistry Institute, University of Campinas-UNICAMP-CEP, P. O. Box 6154, 13084-971 Campinas, SP, Brazil.
Vilcachagua
Janaina D
JD
Neto
Alvaro Cunha
AC
Tormena
Cláudio F
CF
D003198:Computer Simulation; D053138:Cyclohexenes / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D008956:Models, Chemical; D008968:Molecular Conformation; D011789:Quantum Theory; D012015:Reference Standards; D013237:Stereoisomerism
D053138:Cyclohexenes