Degradation of guaiacylglycerol-β-guaiacyl ether in the presence of HS- or polysulphide at various alkalinities Part I.: Degradation rate and the formation of enol ether

The degradation of guaiacylglycerol-beta-guaiacyl ether by HS' and polysulphide was studied at various alkalinities between 0.025 M and 1.1 M OH- at 130 degrees C. Polysulphide strongly suppressed the reverse aldol pathway and thereby the formation of enol ether over the whole [OH] interval investigated. We therefore conclude that polysulphide increases the fragmentation step and probably also acts as a stronger nucleophile than HS' towards intermediate quinone methide structures during the alkaline treatment of guaiacylglycerol-beta-guaiacyl ether. At alkalinities above 0.2M OH- polysulphide tended to degrade the tested beta-model faster than HS-.