Polyene acids. Part IX. Proton magnetic resonance parameters of the muconic esters and mucononitriles

Abstract

From the spectra of the title compounds (at 60 Mc./sec.), proton spin-spin coupling constants and chemical shifts are derived, and an error in previous values for the all-trans-ester is corrected. There is the expected alternation in sign of the couplings. Their values confirm the geometrical configurations of these dienes, and indicate that the molecules are coplanar: thus J_αδ is largest for the all-cis-isomers. Infrared data for the muconic esters are recorded.