3-ethyl-3-phenylazetidinone-2—I. Synthesis of (R)-, (S)- and (RS)-monomer, polymerization and properties of polymers

✍ Scribed by F.J. Carrière; C. Bui; R. Blottiau; H. Sekiguchi

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 512 KB
• Volume: 22
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(86)90194-1

✦ Synopsis

Synthesis and optical resolution of 3-ethyl-3-phenylazetidinone-2 were improved to obtain (RS)-, (R)-and (S)-monomers having optical purities up to 98%, which could successfully be determined by ~H-NMR 250 MHz using tris[3-(2,2,2-trifluoro-l-hydroxymethylidene)d-camphorato]europium III as a shift reagent. These monomers were polymerized anionically in HMPT using potassium salt as a catalyst and by the addition of 1-acetyl-4,4-dimethylazetidinone-2 as a chain initiator. Optical purity of the starting monomer seemed to be maintained in the resulting polymers, the thermal properties of which were found to depend on the mean length of the stereoblocks contained in the chain. While the reactivity, in particular the case of polymerization, of monomer increased with the optical purity, no evidence could be obtained for stereoregulation by a preferential incorporation of a monomer enantiomer according to the configuration of the growing chain end unit.