Fatty acids, Part 28. 1H- and 13C-nuclear magnetic resonance studies of 2,5-disubstituted C18 furanoid ester isomers
Abstract
The 1H n.m.r. spectra of all positional isomeric C18 furanoid fatty esters and the 13C n.m.r. spectra of 12 isomers of the same series are reported. The chemical shifts of the protons and carbons of the methylene groups located between either the methoxycarbonyl and furan system or methyl group and furan system permit facile characterization of the positional isomers. The chemical shifts of the ring protons and carbons provide further confirmation of the characterization of the isomers.