B3LYP DFT 7 (Z)-cinnamic acid 2 13C NMR 2 4-Quinolones 2 Alkylating reagents 2 Alkylation 2 Basic medium 2 Basis set 2 Calculations 2 Carbon-carbon spin-spin coupling constant 2 Carboxylate groups 2 Carboxylation 2 Chemical reactions 2 Cinnamic acids 2 Computation theory 2 Crystal structure 2 DFT calculation 2 Density functional theory 2 EKM 2 Electronic correlation 2 Electronic density of states 2 Electronic structure 2 Energy gap 2 Enthalpies of formation 2 Enthalpy 2 G3 2 G4 2 Gas-phase acidities 2 Gas-phase acidity 2