CHIRALITY INDUCTION IN CYCLOPOLYMERIZATION .2. SYNTHESIS OF OPTICALLY-ACTIVE POLY[(METHYL 4-VINYLBENZOATE)-CO-STYRENE] BY CYCLO-COPOLYMERIZATION OF 1,2 OPROPYLIDENE-3,4-BIS-O-(4-VINYLBENZOYL)-D-MANNITOL AND OPROPYLIDENE-3,4-BIS-O-(4-VINYLBENZOYL)-D-GLUCITOL WITH STYRENE/

opropylidene-3,4-bis-O-(4-vinylbenzoyl)-D-mannitol (1a) and -D-glucito l (1b) with styrene (St) were polymerized using AIBN in toluene at 60 degrees C to yield copolymers (2a and 2b, respectively) consisting ess entially of the cyclic repeating and styrene units. In order to confir m asymmetric induction in 2, the removal of the template from 2 was ca rried out using KOH in aqueous MeOH, and then the resulting hydrolyzed copolymer was treated with diazomethane for conversion into poly[(met hyl 4-vinylbenzoate)-co-styrene] (3). Copolymers 2a and 2b showed a ne gative specific rotation, whereas a positive rotation was observed for 3a and 3b. The CD spectrum of la exhibited a negative Cotton effect a t 300.0 nn and a positive one at 267.3 nm as well as a negative excito n coupling of Ib. According to the exciton chirality method, la and Ib had a negative chirality and its benzoate chromophores, the two 4-vin ylbenzoyl groups, were twisted counterclockwise. On the other hand, th e CD spectrum of 3a (1a/St = 0.30/0.70) and 3b (1b/St = 0.27/0.73) sho wed a split Cotton effect with a positive one at 254.9 nm and a negati ve one at 237.1 nm for 3a and with a positive Cotton effect at 254.7 n m and a negative one at 232.7 nm for 3b. This result indicated that 3 had a positive chirality in which two 4-vinylbenzoyl groups were twist ed clockwise, i.e., the vicinal (methyl 4-vinylbenzoate) groups in the main chain were an (S,S)-configuration.