Chirality induction in cyclopolymerization X. Structural effect of three D-mannitol templates in the cyclocopolymerization of bis(4-vinylbenzoate) with styrene

Three chiral diols. 1,2: 5,6-di-O-isopropylidene-, 1,2: 4,6-di-O-isopropyli dene-, and 1,2: 4,5-di-O-isopropylidene-D-mannitol (a, b, and c, respective ly) were used as template for chirality induction in the cyclocopolymerizat ions of bis(4-vinylbenzoate monomers (1a, 1b, and 1c) with styrene. The chi rality of polymers 3a and 3b was opposite to that of monomers 1a and 1b on their CD spectra. In contrast, the chirality of polymer 3c was the same as that of monomer le. The efficiency of template on the chirality induction d ecreased in the order of b>a>c. The efficiency is lower for template b than the corresponding acyclic template e, though being higher for templates a and c than the acyclic templates d and i, respectively. These characters of the mannitol templates were discussed on the basis of the most suitable co nformer in the monomers.