A triantennary N-acetylgalactosamine (Tri-GalNAcβ) ligand immobilized on long-chain alkylamine (LCAA) controlled-pore glass (CPG, 500Å pore size) for solid-phase oligonucleotide synthesis. The Tri-GalNAc is connected through a (β-D-GalNAc-sp)₃-NHC(O)(CH₂)₁₀C(O) spacer to a 1-(5S-dimethoxytrityloxymethyl)-3-hydroxypyrrolidine, which serves as the 3′-anchor for chain extension. After standard phosphoramidite oligonucleotide synthesis and cleavage from the support, the resulting oligonucleotide carries a 3′-Tri-GalNAc cluster suited for ASGPR-mediated hepatocyte targeting. This compound enables the construction of hepatocyte-targeted therapeutics and research tools that exploit the asialoglycoprotein receptor (ASGPR; Ashwell-Morell receptor), which is highly expressed on liver hepatocytes and binds GalNAc-containing ligands with high affinity. The trivalent presentation of GalNAcβ residues engages multiple carbohydrate-recognition domains of ASGPR simultaneously, producing high-avidity binding that substantially exceeds the affinity of monovalent GalNAc ligands and closely mimics the geometry of clinically validated Tri-GalNAc targeting moieties used in approved GalNAc-siRNA therapeutics.