Mechanochemical reactions of ß-O-4 units of Hgnin were discussed on the basis of thc rcsults from veratryl glycerol-ß-guaiacyl (I) and vanillin (II) ethers and relatcd compounds, which wcrc trcatcd with ceramic ball mill for l hr in air. The homolytic cleavage of aryl cthcr bonds was obscrvcd only in thc compounds containing para -carbonyl group. In particular, the cleavage of Cß-O bond in compound (II) gave vanillin with 18.8% yield.This was followed by the homolytic cleavage of Ca-Cß to givc 3 and 4 and further by emission of formaldehyde to afford 7. However, condensation reaction among radicals also occurred to give 5 and o.These results suggested that mechanical pulp lignin containcd more amounts of para-carbonyl phenol groups compared to those in original wood lignin, and thcrcforc would givc significant effect on pulp bleaching with alkaline hydrogen peroxide.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.