A Pd-Catalyzed Approach to (1→6)-Linked C-Glycosides

A flexible and robust method for the assembly of (1→6)-linked C-glycosidic disaccharides is presented. The key reaction is a Pd-catalyzed coupling of 1-iodo- or 1-triflato-glycals with alkynyl glycosides. Reinstallation of the native hydroxyl group pattern is achieved after selective hydrogenation of the triple bond using Raney-nickel. Epoxidation with DMDO and reductive epoxide opening gives access to either the α- or the β-derivative, depending on the hydride source.