CHIRALITY INDUCTION IN CYCLO-COPOLYMERIZATION - 9 - CHARACTERIZATION OF CHIRALITY INDUCTION DURING THE CYCLOCOPOLYMERIZATIONS OF (2S,3S)-2,3-BUTANEDIYL, (2S,4S)-2,4-PENTANEDIYL, AND (2S,5S)-2,5-HEXANEDIYL BIS(4-VINYLBENZOATE)S WITH STYRENE

Optically active poly(methyl 4-vinylbenzoate-co-styrene)s (3a-c) were synthesized through the cyclocopolymerizations of (2S,3S)-2,3-butanedi yl, (2S,4S)-2,4-pentanediyl, and (2S,5S)-2,5-hexanediyl bis(4-vinylben zoate)s (1a, 1b, and 1c, respectively) with styrene. The extent of chi rality induction increased in the order of 1a congruent to 1c < 1b, an d the cyclized units predominately possessed an (R,R)-configuration. T he MM2 calculation derived the conformer distributions in which monome rs 1a and 1b predominately had a counterclockwise gauche form (''g(-)' ') and a combination of trans form and clockwise gauche form (''tg(+)' '), respectively. Monomer 1c had a nide distribution into ''tg(+)g(+)' ', ''g(+)tg(+)'', and ''ttt'' forms because of flexibility. The semiem prical molecular orbital calculations were performed for the model rea ction of the radical cyclization. The calculated population difference between (R,R)- and (S,S)-configurations indicated that the template i n 1b was more effective for the chirality induction than that in 1a, s imilar to the experimental results.