Base catalyzed deuterium exchange of the hydrogens in the alpha position in 3-pentanone was followed by recording the NMR spectra over a period of approximately an hour with an Anasazi Eft-60 FTNMR spectrometer. The overall reaction kinetics were easily determined by following the disappearance of the signal due to the protons on the carbons alpha to the carbonyl group.

However, it was also possible to independently follow the appearance and subsequent disappearance of partially exchanged species. The exchange process may be represented as the disappearance of a reactant R, the normal isotopomer, appearance and subsequent disappearance of an intermediate I, which is any species with CHD in the alpha position, followed by the appearance of the product with two D's in the alpha position.

The disappearance of R, appearance and disappearance of I and appearance of P could all be followed independently by monitoring the methyl region of the spectrum. The splitting of the methyl proton resonances by deuterium (spin = 1) during the course of the reaction was also observed. This experiment can easily be completed in one undergraduate laboratory period. Similar experiments with asymmetric ketones are underway.

Partial support for this work was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement program under Award No. 0536648. The Welch Foundation is acknowledged for support.