The goal of this study is to better understand important reactions responsible for the suppression of anhydrosugars during the pyrolysis of microcrystalline Avicel, ball-milled Avicel, levoglucosan, cellobiosan, and Douglas fir at varied pyrolysis conditions (heating rate 100°C/s, temperature 300-500°C, H2SO4 addition 0-0.6 wt %) in an atmospheric pressure wire mesh reactor. Pyrolysis of levoglucosan at 300°C yielded 67 wt % of itself, indicating that this is a reactive molecule. Pyrolysis of cellobiosan at 300°C resulted in the production of relatively large quantities of an unidentified compound (estimated in 22 wt %) and a solid residue (18 wt %) with small quantities of levoglucosan. This result suggests that cellobiosan is an important intermediate for char formation during cellulose pyrolysis. When sulfuric acid (0.04 wt %) was added in small amounts to the control and ball-milled cellulose, the yield of levoglucosan decreased and 1,6-anhydrogulcofuranose was formed through accelerated dehydration reactions. In the case of the Douglas fir, an increase in levoglucosan yield (from 30 to 40 wt %) may occur via mitigation of cellulose-lignin interactions in this material or through passivation of the remaining AAEMs (0.013 wt %). At higher acid concentrations the levoglucosan yield decreases, likely due to the acceleration of cellulose dehydration reactions.