POLYMERIC CHIRAL CROWN ETHERS .6. OPTICAL RESOLUTION OF ALPHA-AMINO-ACID BY POLYMERS INCORPORATING 1,3-4,6-DI-O-BENZYLIDENE-D-MANNITOL RESIDUES

The optical resolution of α-amino acid was studied using chiral poly(crown ether)s 2 and 5. The former was prepared from cyclopolymerization of 1, 3;4, 6-di-O-benzylidene-2, 5-bis-O-[2-(2-vinyloxyethoxy)ethyl]-D-mannitol (1), and the latter was obtained from copolymerization of acrylonitrile and macromonomer 4 synthesized through the polymerization of 1 with 2-vinyloxyethyl methacrylate in the presence of hydrogen iodide/iodine. The optical resolution of racemic α-amino acid methyl esters through bulk chloroform containing polymer 2 from one aqueous solution to another was examined. The faster moving enantiomer was the L-isomer, which agreed with the result in the one-plate extraction experiment. On the other hand, thecolumn packed with chiral polymer 2 gave an eluent containing a mixture enriched in the D-isomer when being used for resolution of racemic α-amino acid methyl ester. The D-isomer permeated preferentially through the membrane prepared from copolymer 5 as well. The L-isomer which forms the more stable complex is easily absorbed by the stationary phases, resulting in an excess of the D-isomer in the final mobil phases. © 1990 The Society of Polymer Science, Japan.