Building Multivalent Iminosugar-Based Ligands on Calixarene Cores via Nitrone Cycloadditions

A novel and challenging approach for the construction of multivalent iminosugar architectures directly on calixarene scaffolds is presented, which exploits multiple cycloaddition reactions of a carbohydrate-derived nitrone on diversely functionalized calix[4]arenes. Regardless of the 4-fold reiteration on a single calixarene, the reactions take place with high regio- and stereoselectivity, demonstrating this method as an appealing one for the synthesis of calixarene-based neoglycoconjugates.