Modification of methyl O-propargyl-D-glucosides: model studies for the synthesis of alkynyl based functional polysaccharides

Methyl 4,6-O-benzylidene-2,3-di-O-propargyl-alpha-D-glucoside (2) has been prepared and its structure determined, including its X-ray structural analysis. For comparison the structure of the corresponding allyl derivative has also been determined by X-ray crystallography. Glucoside 2 is a versatile starting material for numerous novel derivatives such as diols, a diester, a diacid, and a dialdehyde. Subjecting 2 to a Mannich reaction leads to a (bis)amine in excellent yields. The click reaction between 2 and benzyl azide furnishes a (bis)triazole as the main product. Deprotection of 2 furnishes a (bis)propargyl ether, which can be converted by the methodology developed for 2 to the corresponding (bis)acetylenes; click reaction with benzyl azide converts 2 into a (bis)triazole.