Addendum—Analysis of First-Order Patterns

The chelate forms a complex with the functional group of the substrates.  

As mentioned in Section 4.16, a chiral shift reagent may be used to resolve mixtures of enantiomers. 

FIGURE 4.55. The 60-MHz proton NMR spectra of 0.40 mL of CDC13 solution containing 0.300 M 1-heptanol at various mole ratios [moles of Eu(dpm), per mole of 1-heptanol] (a) 0.00, (b) 0.19. (c) 0.78. Temperature, 30°C. From Rabenstein, D.L. Anal. Chem., Vol. 43, p. 1599, Copyright 1971 by the American Chemical Society. Reprinted by permission of the copyright owner. 

in recent years, the approach has been to utilize the much higher frequency instruments now available in preference to shift reagents. 

For mixtures of enantiomers, methods other than the use of chiral shift reagents, such as gas chromatography or high-performance liquid chromatography with chiral columns, are now used. Alternatively, the substrate is derivatized with a pure enantiomer of a chiral reagent, and the resulting derivatives are separated by standard gas or liquid chromatography. 

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