EFFECT OF RING SIZE ON THE CATIONIC RING-OPENING POLYMERIZATION OF CYCLIC SULFITES

The cationic polymerization of five- and eight-membered cyclic sulfite s (5CS and 8CS) was examined. The monomer 5CS polymerized in the prese nce of cationic initiators such as TfOMe, BF3. OEt2, and TsOMe in bulk to afford a polyether, accompanied by quantitative desulfoxylation. O n the other hand, 8CS polymerized without desulfoxylation. Ring strain s of 5CS and 8CS were evaluated by molecular orbital (MO) calculations , which confirmed the larger ring-strain of 8CS compared with 5CS.