Preparation, characterization, and porperties of optically active poly(α‐methyl‐α‐ethyl‐β‐propiolactones)

Abstract

Abstract S(−) and R(+) enantiomers of α‐methyl‐α‐ethyl‐β‐propiolactone (MEEPL) were prepared in an eight‐step synthesis with respective optical purities of 99 and 97% determined by 1 H‐NMR (250 MHz) spectroscopy. Polymers (PMEPL) of different enatiomeric compositions were prepared with an anionic‐type initiator. Substantial differences in physical properties were observed between the racemic and optically pure polymers; for example, the melting point of the latter is 42°C higher than that of the former. Chiroptical properties of PMEPLs are reported. The 13 C‐NMR (100.62 MHz) spectra of the polymers indicated that the distribution of configurational units in the macromolecular chain is random.