Structural Elucidation of Bamboo Lignin by Acidolysis and Ozonolysis I.

Abstract

Bamboo lignin was completely degraded into the oligomers composed of monomeric to pentameric products by acidolysis and mild ozonolysis. Model experiment showed that the phenylcoumarone moiety which is known to be produced from the phenylcoumarane structure in lignin in acidolysis is cleaved almost quantitatively to 5-acetyl derivatives and p-hydroxybenzoic acid derivatives by the mild ozonolysis (-70℃). From the monomer fraction of the ozonolysis products of the lignin residue by acidolysis p-hydroxybenzoic acid derivatives (XXI, XVII), methyl p-hydroxybenzoate derivatives (XXII, XXVI, XXVIII), p-cresol derivatives (XVIII, XXIII), p-hydroxybenzaldehyde derivatives (XX, XXV, XXVII), p-hydroxybenzylmetyl ether derivatives (XIX, XXIV) and dimethyloxalate (XXIX) were obtained, respectively.