An α-D-mannose ligand equipped with a terminal alkyne through a hydrophilic PEG3 spacer. The alkyne couples to azide-functionalized partners via copper-catalyzed azide-alkyne cycloaddition (CuAAC), forming stable 1,2,3-triazole linkages. This compound provides an α-D-mannose building block for glycoconjugate synthesis and the construction of probes for mannose-recognizing receptors and lectins, including the mannose receptor (CD206) and DC-SIGN, with relevance to immune-targeting and pathogen-recognition research.