Chemistry of 2,5-dihydroxy-[1,4]-benzoquinone, a Key Chromophore in Aged Cellulosics

2,5-Dihydroxy-[1,4]-benzoquinone is one of the three key chromophores found in aged cellulosics. Knowledge of the general reactivity and chemistry of this compound is helpful for a better understanding of cellulose aging and yellowing as well as bleaching of cellulosic materials - processes which also have considerable economic importance. This paper reviews the reactions reported for 2,5-dihydroxy-[1,4]-benzoquinone, from the viewpoints of both synthesis and general reactivity. The exhibits a rich chemistry because of the presence of both carbonyl and enol motifs, and is able to undergo both nucleophilic and electrophilic substitutions. Other major pathways are the condensation with amines, derivatization of the hydroxyl groups, reductions, and oxidative degradation.