NMR Conformational Investigation of Stereocontrolled Reduction of Lignin-Model Compounds

The stereochemical pathway of the hybride reductions of lignin model compounds (ketoalcohols and ketoesters) was studied in different conditions to obtain a complete information on the erythro/threo ratios, during synthesis of guaiacylglycerol-guaiacylether. The conformation of a cetol in solution and possible transition rates were studied using 1 H and 13 CNMR analysis and it was showed that the presence of polar groups in the molecules is a preponderant factor governing the asymmetric induction