N-Boc-PEG16-alcohol

N-Boc-PEG16-alcohol is a polyethylene glycol (PEG)-based linker building block designed for constructing PROTACs and related targeted protein degradation conjugates. Its PEG spacer provides conformational flexibility and aqueous compatibility, while the N-Boc protecting group supports controlled functional-group handling during synthesis. This product is commonly used to introduce a PEG tether bearing a reactive alcohol handle, enabling downstream coupling to ligands and warheads. The subsequent points describe the linker’s structure and practical reactivity considerations in detail below.

Structure: The molecule consists of a PEG chain terminated by a primary alcohol and capped with an N-Boc carbamate. It contains ether linkages within the PEG backbone, a carbamate carbonyl, and an aliphatic alcohol, providing a flexible, hydrophilic scaffold with hydrogen-bonding capacity and good solubility in polar media.

Reactivity: The alcohol functionality can be leveraged for standard PROTAC linker derivatization via activation to form ester or ether linkages, typically using coupling reagents under mild base conditions. The Boc group is designed for orthogonal protection, enabling selective deprotection with acid to reveal an amine for subsequent amide or urea formation. Common approaches use dry polar solvents and established carbodiimide or acyl-activation chemistries, with purification by chromatography to remove excess reagents.