Synthesis of multivalent beta-1-thiogalactosides through azide-symmetric alkyne Ru(II)-catalyzed cycloaddition

KOVENSKY, JOSE;; ALEJANDRO J. CAGNONI; OSCAR VARELA; MARÍA LAURA UHRIG

Sorrento, Nápoles

Simposio; European Carbohydrate Symposium; 2011

European Carbohydrate Organization

As part of our ongoing project on the synthesis of multivalent glycoclusters designed to be hydrolytically stable in biological media, we describe here the synthesis of multi-thiogalactosides using as key step the Ruthenium(II) catalysed cycloaddition of azidosugars and a disubstituted (internal) alkyne chain carrying two thiogalactoside residues. Glycoclusters containing two or four residues of 1-beta-thiogalactose have been obtained in good yields. Deacetylation led to the final products. After complete characterization by NMR spectroscopy and HR-MS techniques, these new multivalent ligands have been evaluated as inhibitors of E. coli beta-galactosidase. These compounds are interesting as potential modulators of lectin-mediated processes.