Journal of the Chemical Society Perkin Transactions 2 · 1984 · 13 citations · 0 references
Natural SciencesChemistryMedicinal ChemistryOrganic ChemistryPhysical ChemistrySpectroscopyConformational AnalysisHeterocyclic ChemistryIntermolecular ForcesMolecular SymmetryChemical Equilibrium ConstantsConformational Exchange AnalysisEquilibrium ConstantsSubstituent Effects On ConformationSubstituent Effects On Ring Conformation
The position of conformational equilibria due to ring inversion in N-alkyl-cis-decahydroisoquinolines (alkyl = Me, Et, Pri, CH2CF3, or CH2CCl3) has been assessed directly from 13C and/or 19F n.m.r. spectra recorded at temperatures between 173 and 253 K. The measured equilibrium constants are related to the inductive effect of the N-substituent which produces an increase (Me, Et, Pri) or decrease (CH2CF3, CH2CCl3) in the magnitude of the gauche propylamine-type repulsive interaction. 13C Chemical shifts are tabulated for the carbon atoms of the two twin-chair conformations undergoing exchange.