Unusual Transformations of Mono- and Disaccharide Intermediates in the Synthesis of Oligosaccharides Related to Fragments of the Capsular Polysaccharide of Haemophilus influenzae Type e.

In the course of synthesis of oligosaccharides related to fragments of the capsular polysaccharide of Haemophilus influenzae type e, reactions of 2-O-trifluoromethanesulfonate β-D-glucopyranoside derivatives with the azide anion were studied. The reactions gave products of both nucleophilic substitution and rearrangement accompanied by 6-membered pyranose ring contraction to a 5-membered ring through (O5–C2)-cyclization. The formation of these products was interpreted for the first time using quantum mechanical calculations. [ABSTRACT FROM AUTHOR]