SYNTHESIS OF OLIGOMERIC MIMICS OF LIGNIN

The preparation of beta-O-4 oligomeric compounds that mimic the lignin structure is pertinent to the study of the mechanism of action of lig nin-degrading enzymes. A strategy for the synthesis of racemic oligome rs beta-O-4 phenolic models of lignin is reported here. The procedure is quite general with respect to the number of linked units. It starts from simple building blocks that are prepared in a few conventional s teps from commercially available starting materials. The building bloc ks can be classified as three different units, an initiating 3, a repe ating 4 and a terminating unit 5. The combination of these units by al dol-type reactions allows the synthesis of oligomeric materials contai ning the beta-O-4 structure. The procedure allows the determination of the relative configurations of the stereocenters generated in the ald ol-type reactions that provide the beta-O-4 skeleton. The synthesis pr ocedure reported here for the trimer 6 and tetramer 7 can be easily ex tended to higher oligomers and it is suitable also for automated synth esis.