Searching for zwitterionic intermediates in Hetero Diels-Alder reactions between methyl α,p-dinitrocinnamate and vinyl-alkyl ethers

- Reactions of methyl α,p-dinitrocinnamate with vinyl-alkyl ethers have a polar nature.
- Zwitterions may arise during their course reactions.
- Regioselectivity of reactions can be explained on the basis of electrophilicity indices theory.
- M062x functional overestimates activation energies.