Lipophilic Tartaric Acid Esters as Enantioselective Ionophores

Abstract

Abstract Tartaric acid esters with lipophilic alcohol moieties can discriminate between enantiomeric ammonium ions such as norephedrinium ions. Quantitative results were obtained by partitioning the components between water and 1, 2‐dichloroethane. The stereoselectivity was characterized by the free energy difference of the partition process (ΔΔ G ). Diamond‐lattice sectors were used to construct models of the (unstable) lipophilic ester/ammonium salt complexes from X‐ray structures of the individual components (esters and ammonium salts). These models can be used to interpret the effect of structure and configuration of the alcohol moiety on the stereoselectivity and enantioselectivity towards 1‐phenyl‐2‐amino‐1‐propanol (norephedrine) salts.