Stereoselective Synthesis of the Gal‐α‐(1→3)‐Gal‐β‐(1→3)‐GlcNAc Trisaccharide: a new Ligand for DCAR and Mincle C‐Type Lectin Receptors

In this work, we have discovered that the Gal‐α‐(1→3)‐Gal‐β‐(1→3)‐GlcNAc trisaccharide, a fragment of the B antigen Type‐1, is a new ligand of two C‐type lectin receptors (CLRs) i. e . DCAR and Mincle which are key players in different types of autoimmune diseases. Accordingly, we report here on a straightforward methodology to access pure Gal‐α‐(1→3)‐Gal‐β‐(1→3)‐GlcNAc trisaccharide. A spacer with a terminal primary amine group was included at the reducing end of the GlcNAc residue thus ensuring the further functionalization of the trisaccharide Gal‐α‐(1→3)‐Gal‐β‐(1→3)‐GlcNAc.