HO-PEG10-OH

This HO-PEG10-OH linker is a polyethylene glycol-based diol designed to serve as a flexible spacer in PROTAC architectures. Its ether-rich backbone provides conformational mobility and improves the presentation of attached ligands to target proteins, supporting efficient ternary complex formation. The subsequent sections describe its structural attributes and practical considerations for PROTAC assembly using standard coupling strategies.

Structure: The linker consists of a PEG chain terminated by hydroxyl groups, featuring multiple ether linkages along a flexible aliphatic scaffold. It behaves as a hydrophilic, hydrogen-bonding diol, enabling formation of stable covalent bonds to complementary functional groups used in PROTAC synthesis.

Reactivity: As a diol, it is commonly incorporated by converting terminal hydroxyls into activated intermediates or by coupling after functional-group interconversion. Suitable approaches include esterification or ether formation with activated carboxylic acids, and nucleophilic substitution using appropriate leaving groups. Typical conditions employ inert atmospheres, polar aprotic solvents, and established coupling reagents to form robust linker-ligand connections while preserving PEG integrity.