Enantiomer composition determination derivatizing agent

Various chiral derivatizing agents have been reported for the determination of enantiomer compositions. One example is determining the enantiomeric purity of alcohols using 31P NMR.28 As shown in Scheme 1-8, reagent 20 can be readily prepared and conveniently stored in tetrahydrofuran (THF) for long periods. This compound shows excellent activity toward primary, secondary, and tertiary alcohols. To evaluate the utility of compound 20 for determining enantiomer composition, some racemic alcohols were chosen and allowed to react with 20. The diastereomeric pairs of derivative 21 exhibit clear differences in their 31P NMR spectra, and the enantiomer composition of a compound can then be easily measured (Scheme 1-8). 

Also, the enantiomeric purity of the derivatizing agent becomes crucial in the correct determination of enantiomeric composition. The presence of minor amounts of the undesired enantiomer results in inaccurate determinations. Unfortunately, the enantiomeric purity of the chiral reagent is often either lower than 99% or even unknown, thereby preventing the determination of the unwanted enantiomer at the level needed to accomplish the exigencies of the regulatory medicine agencies. 

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