Synthesis of new trimeric lignin model compounds containing 5-5' and beta-O-4' substructures, and their characterization by 1D and 2D NMR Techniques

Trimeric lignin model compounds containing biphenyl (5-5') and beta-aryl ether (beta-O-4') were synthesized from dehydrodivanillin derivatives and alpha-bromo acetovanillone derivatives via Williamson's reaction. The ¹H and 13C NMR characteristics of the resulting trimers were studied using corresponding ¹H and 13C NMR spectra as well as homo- and heteronuclear 2D NMR techniques. The results are discussed in terms of signal assignment and conformation of the molecules.

trimeric lignin model compounds; biphenyl substructure; beta-aryl ether substructure; synthesis; 2D NMR spectroscopy

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