Determining Enantiomeric Excess by Direct NMR Methods and by Indirect Methods

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 1 Issue 3 (1996), S1430-4171(96)01036-1

Determining Enantiomeric Excess by Direct NMR Methods and by Indirect Methods

Robert Rothchild

The City University of New York, John Jay College of Criminal Justice, New York, NY 10019-1199

Published online: 5 August 1996

Abstract. Methods for determination of enantiomeric excess are discussed, with particular emphasis on direct NMR methods using chiral lanthanide shift reagents or chiral solvating agents. Chromatographic (and related) methods are considered. Indirect methods requiring formation of covalently bonded diastereomeric derivatives are also described. The various techniques are compared and contrasted, and they are explained from the standpoint of the rates of the relevant dynamic processes involved, that is according to whether a particular system and measurement method define a slow exchange limit or fast exchange limit regime.

Key Words: In the Classroom; : chiral, lanthanide shift reagents; LSR; chiral solvating agents; CSA; chiral derivatizing agents; CDA; stereochemistry; NMR; analysis; chromatography; GC; HPLC; diastereomers; fast exchange limit; FEL; slow exchange limit; SEL

(*) Corresponding author. (E-mail: na)

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