The condensate from Curie-point pyrolysis of cellulose has been examined as the permethylated derivative and as the borodeuteride-reduced permethylated derivative. The main complete sugar peaks were identified as levoglucosan and cellobiosan. Fragments were also identified which were derived from reverse aldolisation cleavage of a sugar ring to leave acetaldehyde fragments on the reducing and non-reducing ends of intact sugar units. No peaks of significant intensity could be identified as anhydrosugar units with attached ring cleavage fragments.
J. Anal. Appl. Pyrolysis

Lomax, J. A., Commandeur, J. M., Arisz, P. W. F., & Boon, J. J. (1991). Characterisation of oligomers and sugar ring-cleavage products in the pyrolysate of cellulose. J. Anal. Appl. Pyrolysis, 19, 65–79. doi:10.1016/0165-2370(91)80035-7