Synthesis of substituted septanosyl-1,2,3-triazoles

A carbohydrate-based oxepine, derived from 2-deoxy-d-arabino-hexopyranose, was used to prepare a family of septanosyl-1,2,3-triazoles in four steps. DMDO mediated epoxidation of the oxepine followed by trapping of the intermediate 1,2-anhydroseptanose by sodium azide gave the β-substituted glycosyl azide. The septanosyl azide was then reacted with a number of alkynes under thermal Huisgen or copper(I) mediated reaction conditions. Hydrogenolysis of benzyl protecting groups gave substituted septanosyl-1,2,3-triazoles. The new septanose-based structures were then evaluated as potential glycosidase inhibitors.