ANALYSIS OF 2,6-DIARYL-3,7-DIOXABICYCLO[3.3.0]OCTANES AND DIBENZYLBUTYROLACTONES BY PYROLYSIS-GAS CHROMATOGRAPHY MASS-SPECTROMETRY

Twenty compounds of the 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane and dibenzylbutyrolactone series of lignins have been examined by pyrolysis-gas chromatography using an ion trap detector mass spectrometer. Differences between the two series are noted and also situations in which individual structural features dominate the pyrolysis behaviour. In these cases individual marker peaks can be identified which are characteristic of the compound concerned. The most uniform and characteristic fragmentation pattern is associated with the dibenzylbutyrolactones having a benzylic hydroxyl group which undergo a retro-aldol cleavage, giving two major products, which can be used to determine the identity and position of attachment of the benzyl groups present. The variation with temperature of the pyrolysis products from one of the compounds is reported.