Synthesis of α-maleimide-ω-dienyl heterotelechelic poly(methyl methacrylate) and its cyclization by the intramolecular Diels-Alder reaction

The synthesis of heterotelechelic poly(methyl methacrylate) (PMMA) containing alpha-maleimide-omega-dienyl end-groups and its subsequent intramolecular cyclization are described. The anionic polymerization of methyl methacrylate was carried out with 3-tert-butyldimethysilyloxypropyl-1-lithium and 5-bromo-1,3-pentadiene as the initiator and terminator, respectively, to synthesize alpha-hydroxy-omega-dienyl-PMMA. The introduction of the maleimide group to the a chain end by the reaction of the sodium salt of the polymer with N-(3-chloromethylphenyl)-maleimide or N-(3-bromomethylphenyl)maleimide was not successful because of the nucleophilic addition of alkoxide to the carbon-carbon double bond of the maleimide group. When 4,4'-bismaleimidediphenylether was allowed to react with the alkoxide, the aimed alpha-maleimide-omega-dienyl-PMMA was obtained in a good yield. Ring closure by the intramolecular Diels-Alder reaction was carried out by the heating of the dilute polymer solution in tetrahydrofuran. (C) 2000 John Wiley & Sons, Inc.