Coupling reactions of activated oligo(ɛ-caprolactone)s

Summary

Oligo(ɛ-caprolactone)s functionalised with acid groups were prepared by reacting hydroxyl terminated oligo(ɛ-caprolactone)s with succinic anhydride, maleic anhydride or glutaric anhydride. Quantitative conversion of the hydroxyl functionality was achieved in the melt at 130 °C. The resulting acid terminated oligo(ɛ-caprolactone)s were characterised by ¹H and ¹³C NMR spectroscopy. The reactivity of these oligomers was enhanced by conversion of the acid functionality in an acid chloride functionality using thionyl chloride or an anhydride functionality using acetic anhydride. It was shown that these activated oligo(ɛ-caprolactone)s can be used for coupling reactions with compounds containing alcohol- or amino functionalities.