Iterative synthesis of monodisperse PEG homostars and linear heterobifunctional PEG

Abstract

Highly monodisperse, heterobifunctional poly(ethylene glycol) (PEG) was prepared by iterative chain extension of a PEGylated homostar using an octagol (EG8) building block to give MeO-EG24-OH in high purity. The branched structure facilitated purification of intermediates by chromatography, and mono-functionalization of the chain termini. This approach should be extendable to other classes of oligomers. © 2014 The Royal Society of Chemistry.