Simple method for synthesizing phenolic beta-O-4 dilignols

A modified synthetic method for phenolic beta-O-4 lignin substructure model dimers was developed involving protection of the phenolic hydroxyl group o f acetophenons with benzoyl chloride, bromination with 4-dimethylaminopyrid iniumbromide perbromide, condensation with phenols in the presence of 18-cr own-6-ether, condensation with paraformaldehyde, reduction with NaBH4, and debenzoylation. This method results in shorter reaction times and increasin g yields without the application of strict anhydrous and drastic conditions or chloric solvents. This alternative route could be applied to the beta-O -4 dilignol syntheses of four combinations of guaiacyl and syringyl derivat ives.