Synthesis of New Trimeric Lignin Model Compounds Containing 5-5′ and β-O-4′ Substructures, and their Characterization by 1D and 2D NMR Techniques

Abstract

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