ASYMMETRIC RADICAL CYCLOPOLYMERIZATION OF N-ALLYL-N-PHENYLMETHACRYLAMIDE IN THE PRESENCE OF SNCL4 AND L-MENTHOL

Asymmetric induction was examined in the cyclopolymerization and cycle copolymerization of N-allyl-N-phenylmethacrylamide (PAMA) with dimeth yl 2,2'-azobis(isobutyrate) in benzene in the presence of L-menthol an d SnCl4. Optical activity ([alpha](D) = -0.3 to -5.6) was observed for poly(PAMA)s formed in the radical polymerization of the PAMA/SnCl4/L- menthol system. The PAMA monomer unit was incorporated exclusively as a five-membered ring into the highly cyclized poly(PAMA)s (degree of c yclization (DC)= 95-98%) obtained. The radical copolymerization of PAM A with methyl methacrylate in the presence of L-menthol and SnCl4 also gave optically active copolymers, the PAMA. units of which were simil arly highly cyclized (DC = 90-94%) as a five-membered ring. The [alpha ]D value of the copolymer increased up to [alpha](D) = -15.2 with incr easing PAMA concentration in the feed. The much lower DC values (25-68 %) of the PAMA monomer unit were observed for the copolymers formed in the copolymerization of the PAMA/styrene/L-menthol/SnCl4 system. Howe ver, the copolymers showed a considerable optical activity ([alpha](D) = -9.1 to -11.8).