The synthesis pathways to obtain HA-NB and HA-AE were refined from reported one-step processes in non-toxic solvents. To synthesize HA-AE, the primary alcohol group on the C-6 of the N-acetyl-d-glucosamine unit in HA was deprotonated in basic medium and reacted with allyl glycidyl ether through a nucleophilic ring opening reaction (Scheme 1A). The functionalized polymer was purified by precipitation and dialysis and lyophilized. The derivatization of the HA was corroborated by 1 H NMR spectroscopy. The vinyl protons of AE appeared between 5.15 and 5.36 ppm and confirmed the presence of the allyl group. The Fene was determined by the integral ratio of the vinyl protons relative to the acetyl group of HA (δ = 2.03 ppm) to give Fene = 0.42 ± 0.03. SEC analysis of HA-AE showed no significant differences between the elugrams of HA and