Distribution of substituents in O-carboxymethyl and O-cyanoethyl ethers of inulin

The distribution of substituents in O-carboxymethyl and O-cyanoethyl ethers of inulin was studied using 13C NMR spectroscopy and HPLC analysis. For both types of inulin derivatives, the distribution of substituents can be described by the statistical model of Spurlin, showing that the substituents are uniformly distributed along the inulin chains and that the reactivities of the hydroxyl groups in the sugar units are independent upon substitution of a neighbouring hydroxyl group. The 4-position of the d-fructofuranosyl units was found to be the most reactive in the etherifications.