MACROMOLECULAR IONOPHORES .1. CHIRAL RECOGNITION PROPERTIES OF POLY[(1-]6)-2,5-ANHYDRO-D-GLUCITOL] TOWARD RACEMIC AMINO-ACID ESTER

The chiral recognition property of oly[(1-->6)-2,5-anhydro-3,4-di-O-al kyl-D-glucitol] (1) toward racemic RCH (CO2CH3)NH3+. PF6- (2 . HPF6) h as been studied using a transport system involving an aqueous source a nd receiving phases separated by a chloroform phase containing 1, Tran sport rates for aromatic guests 2a (R = Ph) and 2b (R = CH(2)Ph) were faster than those for aliphatic guests, 2c (R = CH(CH3)(2)) and 2d (R = CH2CH(CH3)(2)), using the polymer substituted with methyl groups (1a ), The enantiomeric excess (e.e.) was 10.9% for 2a as a maximum value and decreased in the order of 2a > 2c > 2b = 2d, When the transport of 2a . HPF6 was carried out using the polymers with 3,4-di-O-methyl (1a ), ethyl (1b), allyl (1c), and pentyl (1d) groups, the e.e. was 22.0% for 1d as a maximum value and increased in the order of 1a < 1b < 1c < 1d, The formation of a complex between 1a and 2a . HPF6 was confirmed by H-1 and C-13 NMR spectral measurements. (C) 1995 Wiley-Liss, Inc.