New Aldehyde-Functional Methacrylic Water-Soluble Polymers.

Aldehyde groups enable facile conjugation to proteins, enzymes, oligonucleotides or fluorescent dyes, yet there are no literature examples of water-soluble aldehyde-functional vinyl monomers. We report the synthesis of a new hydrophilic cis-diol-based methacrylic monomer (GEO5MA) by transesterification of isopropylideneglycerol penta(ethylene glycol) using methyl methacrylate followed by acetone deprotection via acid hydrolysis. The corresponding water-soluble aldehyde monomer, AGEO5MA, is prepared by aqueous periodate oxidation of GEO5MA at 22 °C. RAFT polymerization of GEO5MA yields the water-soluble homopolymer, PGEO5MA. Aqueous periodate oxidation of the terminal cis-diol units on PGEO5MA at 22 °C affords a water-soluble aldehyde-functional homopolymer (PAGEO5MA). Moreover, a library of hydrophilic statistical copolymers bearing cis-diol and aldehyde groups was prepared using sub-stoichiometric periodate/cis-diol molar ratios. The aldehyde groups on PAGEO5MA homopolymer were reacted in turn with three amino acids to demonstrate synthetic utility.