ACID HYDROLYSIS BEHAVIOR OF SYRINGYL TYPE LIGNIN-CARBO-HYDRATE COMPLEX (LCC) MODEL COMPOUND

摘要

Erythro/threo mixture of an α-ethyl ether of veratrylgrycerol-β-guaiacyl ether (VSE) gave the equilibrium mixture after the acid hydrolysis. The conversion of each stereoisomer of VSE into the corresponding isomers of VS was discussed kinetically. The obtained values of z_1 for the conversion of VSE1 into the threo isomer of VS, and z_2 for the conversion of VSE2 into the erythro isomer of VS, were 1.0 and 0.841, respectively. It is suggested that VSE1 and VSE2 should be the erythro and threo isomers of VSE, respectively. Consequently, it could be concluded that acid hydrolysis of the erythro isomer of VSE proceeded with complete inversion of configuration in contrast to that of the corresponding isomer. It is suggested that such difference between both isomer of VSE during acid hydrolysis should be due to the difference of easiness of formation and the stability between benzylcations formed by both.