Effect of catalysts on asymmetric induction cationic copolymerization of l-menthyl vinyl ether with indene

Cationic copolymerization of l-menthyl vinyl ether (l-MVE) with indene (IN) was carried out with several catalysts in toluene (Tol) at 0°C. The catalysts used were BF₃OEt₂, CH₃COClO₄, and SnCl₄. l-Menthyl residue, an optically active side chain of the copolymer obtained, was removed with dry hydrogen bromide gas by the ether cleavage reaction. Ether-cloven copolymers [vinyl alcohol(VA)–IN] also had optical rotation. The efficiency of asymmetric induction to the polymer main chain was in the order of BF₃OEt₂ > CH₃COClO₄ > SnCl₄.