Application of Artificial Polyamides, Having Cyclobutane Rings in the Main Chain, as Chiral Stationary Phases for Hplc

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The phenolic hydroxyl groups in optically active polyamides, which consist of anti head-to-head coumarin dimer, were easily carbamoylated with several kinds of isocyanates in high yield and conversion. HPLC coumns were prepared by coating the polyamides on silica gel surface. The carbamoylated polyamides showed a chiral recognition ability for the racemates, which could not be recognized by the parent polyamides. Consequently, the carbamoylated and parent polyamides showed complementary recognition ability.The chiral recognition ability of polyamides, consisting of anti head-to-head coumarin dimer and alpha, omega-alkanediamine, depended on the methylene number of the diamine component and showed odd-even dscrimination. The X-ray diffraction and DSC analyses revealed that the chiral recognition ability appeared only for the polyamides, which could crystallize on the surface of silica gel and that the higher crystallinity resulted in the higher chiral recognition ability. This result is … More the first example for the elucidation of the correlation between chiral recognition ability, crystallinity, and odd-even discrimination.Polyamides, derived from anti head-to-head umbelliferone dimer, showed steep decrease of their viscosity in an alkaline solution, whereas polyamides consisting of anti head-to-head coumarin dimer were rather stable in an alkaline solution. This phenomenon was found to result from the scission of the main chian via a quinoid from of dihydroxyphenyl groups in the side chain.Anti head-to-head umbelliferone dimer was successfully resolved into enantiomers with high optical purities. The ring-opening polyaddition reaction of the optically active dimer with diamines proceeded very smoothly to give the corresponding, optically active polyamides. Some of them existed in ordered conformation in a solution and/or film state. The polyamides, however, unfortunately showed no chiral recognition ability, which would come from the strong hidrogen bonding between the hydroxyl group at C7 and a solute. Less