Interaction entre groupes aromatique et polaire voisins—III: Synthese et etudes physico-chimiques d'acides p-x-phenyl-3 bicyclo[2.2.1] heptene-5 carboxyliques-2 et de leurs esters methyliques

The synthesis, ¹H and ¹³C NMR spectra of acids 1 to 4 and methyl esters 5 to 8 are described. Interaction of aromatic and polar groups in the cis acids must be steric in origin and not due to charge transfer complex or hydrogen bonding. The structure of 1e,3a,5e and 7e has been determined by X-Ray crystallography. ¹H and ¹³C NMR studies indicate that, in the cis compounds, the proximity of aromatic and polar groups tend to impose to them some largely predominant conformations which should be analogous in the crystal or in solution.