Some Approaches to Glycosylated Versions of Methyl β-Acarviosin

Abstract

In a first approach to a glycosylated version of ‘methyl β-acarviosin’, a putative inhibitor of cellulases, cellobiose was converted into a carbocyclic enone that could not be transformed into the required amine for a subsequent alkylation. Alternatively, methyl β-acarviosin itself was glycosylated at C4′, using a ‘glycosynthase’, to provide the ‘trisaccharide’ (and some ‘tetrasaccharide’). Both of these molecules were effective inhibitors of various cellulases. In a related approach to a regioisomer of the above ‘trisaccharide’, a selectively protected derivative of 1-epivalienamine was alkylated with a carbohydrate triflate to give a ‘disaccharide’ that could not be glycosylated to give the desired ‘trisaccharide’. Another unsuccessful approach to this molecule is also reported.