The influence of protective groups in sialyl halides on their reactivity and selectivity in glycosylation reactions: implications for the mechanism of sialylation.

In this study, a comparative analysis of the reactivity of known and novel sialyl donors bearing various protective and leaving groups (sialyl chlorides and sialyl bromides) was conducted through their reactions with methanol and isopropyl alcohol in the absence of added promoter. NMR analysis of the reaction mixtures following solvolysis provided clear insights into the variations in reactivity and selectivity as a function of the nature of the protective and leaving groups present in the sialyl halide molecules.