First Example of Cationic Ring-Opening Polymerization of γ-Thionobutyrolactone

This paper deals with the cationic ring-opening polymerization of γ-thiobutyrolactone (2) and γ-thionobutyrolactone (3). The ring-opening polymerization of 3 was carried out in bulk at 100 °C for 2 h by various cationic initiators. Scandium trifuoromethane-sulfonate induced the polymerization of 3, which did not afford polythionoester but polythioester selectively. On the other hand, the polymerization of 2 did not proceed with various cationic initiators under the similar conditions.