Delignification Mechanism During High-Boiling Solvent Pulping.Ⅴ. Reaction of Nonphenolic β-O-4 Model Compounds in the Presence and Absence of Glucose

摘要

Nonphenolic β-aryl ether model compounds, veratrylglycerol-β-guaiacyl ether (1) and its α-ethyl ether (2) were treated in 70% aqueous 1, 4-butanediol solutions at 180℃. The reactivity of compound 2 was higher than that of compound 1. Benzyl ether formation with 1, 4-butanediol was observed. This suggests the high reactivity of lignin-carbohydrate complex with benzyl ether type under HBS pulping conditions. On the other hand, guaiacol was not detected in the reaction mixture. This indicates that β-aryl ether in nonphenolic structures is inert to HBS pulping conditions. Addition of glucose and acetic acid enhanced the benzyl ether formation with 1, 4-butanediol, but not cleavage of β-aryl ethers.