TY - JOUR
T1 - Chiral discrimination studies of (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid by high-performance liquid chromatography and NMR spectroscopy
AU - Lee, Wonjae
AU - Bang, Eunjung
AU - Baek, Chae Sun
AU - Lee, Weontae
PY - 2004/4
Y1 - 2004/4
N2 - Chiral discrimination studies using (+)-(18-crown-6)-2,3,11,12- tetracarboxylic acid (18-C-6-TA) as a chiral selector were performed by high-performance liquid chromatography (HPLC) and NMR spectroscopy. The enantiomers of alanine (Ala) or alanine methyl ester (Ala-ME) were well separated on the chiral stationary phases (CSPs) derived from (+)-18-C-6-TA by HPLC. The chiral selector, (+)-18-C-6-TA, used in the CSP was also applied for the chiral discrimination of the Ala and Ala-ME enantiomers, and it discriminated these enantiomers successfully by NMR spectroscopy. The chemical shift differences (ΔΔδ) of the α-proton of these enantiomers in the presence of an equimolecular solution of 18-C-6-TA were observed to be 0.10 ppm for Ala in methanol-d4 containing 10 mM H2SO4 and 0.11 ppm for Ala-ME in methanol-d4. The observed NMR results agreed with the chromatographic data on the (+)-18-C-6-TA-derived CSP by HPLC in terms of both the elution order and solvents effects.
AB - Chiral discrimination studies using (+)-(18-crown-6)-2,3,11,12- tetracarboxylic acid (18-C-6-TA) as a chiral selector were performed by high-performance liquid chromatography (HPLC) and NMR spectroscopy. The enantiomers of alanine (Ala) or alanine methyl ester (Ala-ME) were well separated on the chiral stationary phases (CSPs) derived from (+)-18-C-6-TA by HPLC. The chiral selector, (+)-18-C-6-TA, used in the CSP was also applied for the chiral discrimination of the Ala and Ala-ME enantiomers, and it discriminated these enantiomers successfully by NMR spectroscopy. The chemical shift differences (ΔΔδ) of the α-proton of these enantiomers in the presence of an equimolecular solution of 18-C-6-TA were observed to be 0.10 ppm for Ala in methanol-d4 containing 10 mM H2SO4 and 0.11 ppm for Ala-ME in methanol-d4. The observed NMR results agreed with the chromatographic data on the (+)-18-C-6-TA-derived CSP by HPLC in terms of both the elution order and solvents effects.
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U2 - 10.1002/mrc.1353
DO - 10.1002/mrc.1353
M3 - Article
C2 - 15022200
AN - SCOPUS:10944273385
SN - 0749-1581
VL - 42
SP - 389
EP - 395
JO - Magnetic Resonance in Chemistry
JF - Magnetic Resonance in Chemistry
IS - 4
ER -