The disclosed traceless tethering approach offers a practical synthetic route for drastic modification of the carbocyclic skeleton in native sugars, allowing rapid access to non-typical C-functionalized sugar conjugates without the use of protecting groups and with full control over site-selectivity. The stereochemical outcome of the C-functionalization reaction is firmly controlled by the anomeric configuration of the sugar substrate, furnishing equatorial addition products for α-glycosides and a mixture of equatorial and axial adducts for β-glycosides. The disclosed protocol operates under mild photoredox-mediated conditions, tolerates a wide range of sensitive aglycones and coupling partners, and is easily amenable to scale-up, allowing access to C-alkylated and C-alkenylated sugar derivatives, including α-amino acid-decorated and pseudodisaccharide assemblies. While the described approach illustrates C-functionalization of native sugars proceeding through 1,6-HAT from the primary alcohol functionality, it also opens up numerous possibilities for further development of related traceless tethering systems targeting activation of other carbohydrate skeleton sites.