Easy synthesis and ring-opening polymerization of 5-Z-amino-δ-valerolactone: New degradable amino-functionalized (Co)polyesters

Novel 5-Z-amino-δ-valerolactone (5-NHZ-VL) was synthesized with an aim to prepare degradable polyesters and copolyesters having amino pendant groups. Following a straightforward and efficient synthetic pathway, 5-NHZ-VL was obtained in only two steps and up to 50% yield. The monomer was fully characterized by H NMR, C NMR, ESI mass spectrometry, and HPLC. Various conventional conditions were tested for this lactone ring-opening polymerization and led to the novel corresponding poly(5-NHZ-VL) (Mn = 7000 g/mol; PD = 1.2). Following this homopolymerization, 5-NHZ-VL was copolymerized with Îμ-caprolactone to generate a family of copolyesters with an amino-group content ranging from 10 to 80%. Finally, the polyelectrolyte poly(5-NH3 +-VL) was recovered by removal of the protecting group under acidic conditions, and integrity of the polyester backbone was confirmed by H NMR.