NMR determination of enantiomers of 7‐chloro‐3,3a‐dihydro‐2‐methyl‐2H,9H‐isoxazolo[3,2‐b][1,3]benzoxazin‐9‐one using chiral shift reagent, tris[3‐(heptafluorobutyryl)‐d‐camphorato]europium(III)

1976 ◽  
Vol 65 (4) ◽  
pp. 592-594 ◽  
Author(s):  
Philip Reisberg ◽  
Ian A. Brenner ◽  
Jerome I. Bodin
Keyword(s):  
Shift Reagent ◽  
Chiral Shift Reagent

A new chiral shift reagent for the determination of enantiomeric excess and absolute configuration in cyanohydrins

2009 ◽  
pp. 1067 ◽  
Author(s):  
Lomary S. Moon ◽  
Ravinder S. Jolly ◽  
Yoganjaneyulu Kasetti ◽  
Prasad V. Bharatam
Keyword(s):  
Absolute Configuration ◽  
Enantiomeric Excess ◽  
Shift Reagent ◽  
Chiral Shift Reagent

ChemInform Abstract: A New Chiral Shift Reagent for the Determination of Enantiomeric Excess and Absolute Configuration in Cyanohydrins.

ChemInform ◽  
2009 ◽  
Vol 40 (22) ◽  
Author(s):  
Lomary S. Moon ◽  
Ravinder S. Jolly ◽  
Yoganjaneyulu Kasetti ◽  
Prasad V. Bharatam
Keyword(s):  
Absolute Configuration ◽  
Enantiomeric Excess ◽  
Shift Reagent ◽  
Chiral Shift Reagent

Lanthanide Induced Enhancement of Enantiomeric Shifts in Chiral Solvents and its Use in the Determination of Optical Purity

1973 ◽  
Vol 51 (22) ◽  
pp. 3726-3732 ◽  
Author(s):  
C. P. R. Jennison ◽  
Donald Mackay
Keyword(s):  
Chemical Shift ◽  
Fractional Crystallization ◽  
Sulfonic Acid ◽  
Optical Purity ◽  
Shift Reagent ◽  
Lanthanide Shift Reagent ◽  
Chemical Shift Difference ◽  
Chiral Shift Reagent ◽  
Simple Molecules

The chemical shift difference (Δv) between corresponding groups in enantiomers in the presence of both a chiral solvent ((−)-2,2,2-trifluorophenylethanol or (+)-1-phenylethylamine) and an achiral lanthanide shift reagent (Eu(dpm)3 or Eu(fod)3) is much greater than in the chiral solvent alone. In general, for simple molecules having one coordination site the Δv was smaller than that obtained with the chiral shift reagent Eu(HFC)3. Comparable values of Δv, however, were obtained with the 1,3,4-oxadiazine derivatives 4a and b, and 5, suggesting that the "chiral solvate shift system" is best suited to differentiating more complex enantiomers having several coordination sites.The shift system was used to determine the optical purity of two partially resolved substances. One of these was the (+)-oxadiazine 4a, produced in the asymmetric isomerization of the bridged pyridazine 3a by (+)-camphor-10-sulfonic acid, and optically enriched by only one fractional crystallization. The enantiomeric enrichment in the isomerization was 4.21 ± 0.08%.

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