HO-PEG11-OH

HO-PEG11-OH is a polyethylene glycol-based bifunctional linker designed to support targeted protein degradation workflows by providing a hydrophilic, flexible spacer between a ligand and an E3-recruiting or target-binding module. Its ether-rich backbone and terminal alcohol functionalities help maintain solubility and reduce non-specific interactions, which can improve PROTAC handling and conjugation efficiency. The points below describe its structure and practical reactivity for PROTAC assembly.

Structure: HO-PEG11-OH is a PEG chain bearing terminal primary alcohol groups. The repeating ether units provide a flexible, polar scaffold with ether linkages and hydroxyl termini, enabling strong hydrogen-bonding interactions and high aqueous compatibility. This architecture supports spacing control and minimizes steric constraints between conjugated moieties.

Reactivity: The terminal alcohols enable PROTAC construction via standard hydroxyl-to-linkage transformations, including esterification or ether formation with appropriately activated carboxylic acids or halide/activated electrophiles. Typical approaches use coupling reagents for ester formation or base-mediated substitution for ether linkages, often in polar aprotic solvents. Reaction conditions are chosen to preserve sensitive ligand functionalities and to minimize PEG oxidation or side reactions; purification is commonly performed by chromatography or precipitation-based methods.