THE SYNTHESIS AND CHEMICAL STRUCTURES OF TETRAMERIC LIGNIN MODEL COMPOUNDS

In order to study the reaction of high molecular weight residual ligni n in pulp with chlorine dioxide, three types of tetrameric lignin mode l compounds were designed and synthesized. All three tetramers contain diphenylmethane condensation - type structures but 1 also contains a biphenyl structure and 3 contains beta-arylether linkages. Synthesis o f tetramer 1 involved oxidative coupling of vanillin followed by reduc tion and condensation with an excess of creosol under alkaline conditi ons. Tetramer 2 was prepared by the condensation of vanillin with form aldehyde followed by reduction and condensation as for tetramer 1. Pre paration of tetramer 3 was accomplished by condensation of a dimer con taining a beta-aryl ether linkage with formaldehyde.