Ring-opening polymerization of bicyclic oxalactones and oxalactams

Several bicyclic oxalactones and oxalactams having a bicyclo[2.2.2]octane skeleton were synthesized and their ring-opening polymerizations were investigated under various conditions. These monomers, except 2-oxa-6-azabicyclo[2.2.2]octan-5-one (23), gave the corresponding polyesters or polyamides containing tetrahydropyran rings in their main chains. The anionic polymerization of the bicyclic oxalactam 23 afforded a dimer adduct (24) in low yield, whereas the cationic polymerization of 23 gave oligoethers (28) having six-membered lactam rings in the main chains. The structure-polymerization reactivity relationships for these bicyclic monomers are discussed.