Allyl functionalities can successfully be introduced to different
galactose-containing polysaccharides, such as spruce galactoglucomannan,
guar galactomannan, and tamarind xyloglucan. By
combining oxidation by galactose oxidase with an indium mediated
allylation reaction the galactose units can selectively be derivatized
by allyl halides. The same reaction procedure can also be
applied for spruce galactoglucomannan when using propargyl bromide
as halide. All reactions were carried out by using water as
the only solvent, thus the polysaccharides were functionalized in
a one-pot reaction. Reactivity differences among the polysaccharides
can be observed: oxidized GGM and XG reacted completely
with allyl bromide, whereas for GM approx. only 50% of the aldehydes
were allylated. Still, because of the high galactose content of
GM, allylation of GM produces the polysaccharide with the highest
DS.