The regiospecific radical polymerization of vinyl methacrylate (VMA), a divinyl compound with two different radically polymerizable double bonds, was investigated in the presence of Lewis acids, such as SnCl4, EtnAlCl3-n, and RnAl(ODBP)(3-n) [R = Me, Et, i-Bu; ODBP = 2,6-di-tert-butylphenoxyl. The polymerization with a,a-azobis(isobutyronitrile) (AIBN) in the presence of aluminum-based Lewis acids gave soluble polymers, in which the methacryloyl group was selectively polymerized, while insoluble polymer gels were obtained without Lewis acids or with SnCl4. When using monoalkylaluminum bulky diphenoxides [RAl(ODBP)(2)], the highly regiospecific radical polymerization significantly proceeded with a high conversion (>85%) to give soluble polymers with quantitatively remaining vinyl ester pendants and a relatively high molecular weight (M-n >= 104). The copolymerization of VMA with methyl methacrylate in the presence of EtAl(ODBP)(2) induced the simultaneous consumption of both monomers at almost the same rate to directly give soluble random pendant-functionalized copolymers with vinyl ester moieties. The NMR analysis of the mixture of VMA and EtAl(ODBP)(2) showed a 1:1 complexation with a relatively high association constant (K-assn = 59.6 M-1) via the coordination of the aluminum Lewis acid to the carbonyl moiety. The ruthenium-catalyzed living radical polymerization of VMA was also possible in the presence of EtAl(ODBP)(2) and an iodide initiator to give soluble polymers with controlled molecular weights.