Enzymes in polymer chemistry, 7. Lipase‐catalyzed esterification of carboxyl‐terminated methacrylic oligomers and copolymers with isopropyl alcohol and 9‐fluorenylmethanol

The carboxylic group of the oligoester α‐(11‐methacryloylaminoundecanoyl)‐ω‐hydroxy‐oligo(oxyundecamethylenecarbonyl) (1) was enzymatically esterified with isopropyl alcohol and 9‐fluorenylmethanol, respectively, in the presence of the lipase from Candida cylindracea. Moreover, the oligoester 1 was copolymerized with styrene and subsequently esterified with isopropyl alcohol by the same lipase. The degree of esterification and transesterification was determined by 1H NMR spectroscopy. Esterification occurred almost quantitatively, together with some transesterification, in the case of isopropyl alcohol, whereas with 9‐fluorenylmethanol only a degree of esterification as low as 30% was achieved. The formation of the enzymatically esterified oligoester units was proved by FAB mass spectrometry.