Iodoacetate relative reactivity

The carboxymethylation of cellulose with sodium chloroacetate in an aqueous system generally showed that the 2-OH group was more reactive than the 6-OH group, whereas the 3-OH was the least reactive. A low water content medium resulted in a relatively more uniform reactivity than a high water content reaction [202]. Similarly, carboxymethylation in a nonaqueous system (SO2-DEA-DMSO) [79] resulted in a more uniform reaction and a higher reactivity of the 6-OH group as compared to an aqueous reaction. Interestingly, carboxymethylation with sodium iodoacetate substantially enhanced the reactivity of the 3-OH, which was found to be most reactive under this condition. 

---