A Rapid 1H NMR Assay for Enantiomeric Excess of α-Substituted Aldehydes

In situ derivatization of a variety of α-substituted aldehydes via reaction with chiral amines allows convenient and efficient determination of enantiomeric excess. 1H NMR analysis of the imine diastereomer ratio can be conducted immediately after the aldehyde and amine have been mixed. The results correlate well with ee values determined by more traditional (and slower) methods. This approach may be broadly applicable to α-substituted aldehydes.