Stereoselective synthesis of neo-C-glycopeptide building blocks: Towards a flexible and control-oriented design as probes for carbohydrate-protein interactions

Neo-C-glycopeptides (1–4) have been synthesized as building blocks to obtain higher neo-C-glycopeptides as probes for studying carbohydrate-protein interactions. A convergent approach for the synthesis of 4 has been developed, in which two galactose units are attached to a glycine derivative in a stepwise procedure (reductive amination followed by amide coupling) and finally coupling to the protected dipeptide having a free amino group on the side chain.