Synthesis of X(Y)-(EO)n-OCH3 Type Heterobifunctional and X(Y)-(EO)n-Z Type Heterotrifunctional Poly(ethylene glycol)s

A synthetic route to prepare acetal-protected heterobifunctional poly(othylene glycol), allyl(1-ethoxyethoxy)-PEG-OH (allyl(EE)-PEG-OH), was successfully established using a newly synthesized initiator, trimethylolpropane allyl (1-ethoxyethoxy) ether (TMPAEEE). Heterobifunctional allyl(OH)-mPEG and heterotrifunctional allyl(OH)-PEG-alkyne were obtained, respectively, after modification From this precursor polymer. The polymers were characterized by SEC, H-1 NMR, and MALDI-TOF mass spectroscopy. This approach is applicable for synthesizing a wide variety of X(Y)-(EO)(n)-OCH3 type heterobifunctional and X(Y)-(EO)(n)-Z type heterotrifunctional PEGs.