2-(multimethoxy)phenyl-4-methylene-1,3-dioxolane (I): Preparation and cationic polymerization of 2-(dimethoxy)phenyl-4-MDO derivatives

The 4-methylene-1,3-dioxolane (4-MDO) derivatives with dimethoxyphenyl grou p on the 2-position of 1,3-dioxolane ring, 2-(x,y-dimethoxyphenyl)-4-MDO de rivatives (x,y = 2,3 (Ib), 2,4 (2b), 2,5 (3b) and 3,4 (4b)) were prepared b y acetalization of the corresponding benzaldehyde with 3-chloro-1,2-propane diol, followed by dehydrochlorination. 2-(Dimethoxy)phenyl-4-MDO derivative s underwent polymerization with ring opening as well as cyclization reactio n to afford a mixture of the ring-opened polymer and 3(2H)-dihydrofuranone derivatives with boron trifluoride as a cationic catalyst. Both the methyle ne group and 1,3-dioxolane ring were participated in the reaction with cati onic catalyst. The key intermediate of the polymerization is a benzyl catio n generated by ring opening, and the cyclization reaction proceed via proto n addition to oxygen atom of 1,3-dioxolane ring.