Polymerization of α,α‐disubstituted β‐propiolactones and lactams. VII. Stereoregular polymers from optically active lactones

Optically active α‐phenyl‐ααethyl‐β‐propiolactone of high optical purity was prepared and polymerized by homogeneous anionic initiation to the isotactic polyester. The racemic and isotactic polymers had apparently different crystalline properties suggesting that the former may be syndiotactic or may crystallize with unit cells containing both R and S blocks. Similar attempts to prepare α‐methyl‐α‐isopropyl‐β‐propiolactone of high optical purity were unsuccessful although a partially crystalline polymer was obtained from the racemic monomer.