Reactivity of both phenolic and non-phenolic lignin model compounds with β-O-4 bond was examined using HCl, HBr or H2SO4, to investigate the effect of the presence of phenolic hydroxy group and the type of acid. The most common C6-C3-type phenolic model compound (GG) was acidolyzed much more rapidly than the correspoding non-phenolic analogue (VG). Significant amounts of the primary C6-C3-type Hibbert’s Ketone and its isomer were detected in the acidolysis of phenolic compound (GG) using H2SO4, while in the case of non-phenolic compound (VG), the major reaction product was exclusively C6-C2-type Hibbert’s monomer afforded by the liberation of γ-hdroxymethyl group as formaldehyde. The phenolic Hibbert’s Ketone product compound was less stable than the non-phenolic Hibbert’s Ketone compound and was easily converted into its isomer (α-carbonyl group compound). The same comparisons of “phenolic and non-phenolic” were also performed in the acidolyses of C6-C2-type model compounds and the results obtained is in accordance with that of C6-C3-type model compounds. Although the disappearance of C6-C2-type phenolic or non-phenolic compound was faster for acidolysis using HBr than that using HCl, , the phenolic or non-phenolic enol ether (the exclusive primary reaction product from the phenolic or non-phenolic compound) disappeared with almost the same rate in the acidolysis using either HBr or HCl. This result suggests that Br anion decisively participates only in the disappearances of C6-C2-type compounds to undergo their conversions to enol ethers without influencing the subsequent disappearance of the enol ethers. 

Effect of phenolic hydroxy group and type of acid on lignin acidolysis

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.