Oligomerization of ɛ-caprolactone and δ-valerolactone using heteropolyacid initiators and vanadium or molybdenum complexes

Preparation of the oligomers of ɛ-caprolactone and δ-valerolactone having reactive functional groups, such as hydroxyl and carboxyl groups, were studied in the presence of “heteropolyacids/O2/solvent” or “VOSO4·5H2O/THF-H2O/O2” systems. These oligomers were characterized by various physicochemical techniques.