A novel and unusual polymer topology, i.e. a-ring-with-two-branches, has been constructed efficiently by making use of an interiorly functionalized poly(tetrahydrofuran) (poly(THF)) having two pyrrolidinium groups. The dicarboxylate counterion, i.e. terephthalate, was then introduced by an ion-exchange reaction of the interiorly located pyrrolidinium group. Subsequent heat treatment under appropriate, dilution caused an efficient polymer cyclization to produced an a-ring-with-two-branches polymer topology in high yield through the selective and quantitative ring-opening of the pyrrolidinium groups by the dicarboxylate counterion.