Conformations of E-2-phenyl-3(2′-furyl)propenoic acid and its methyl ester in various solvents—an NMR study

The conformations of E-2-phenyl-3(2′-furyl)propenoic acid and its methyl ester were investigated by NMR spectroscopy. Applying various solvents (methanol, chloroform and dimethyl sulfoxide) the possible conformers in solutions were studied by two-dimensional NOESY measurements. Irrespective to the solvents and whether the investigated moiety was the ester or the acid dimer, no conformational preferences could be identified experimentally.