Multiple deuteration of water-soluble olefinic acids with a [Pd(alizarin monosulfonate)(2)] catalyst

Hydrogenations in aqueous systems with the soluble [Pd(alizarin monosulfona te)(2)] catalyst resulted in extensive deuteration of crotonic, trans-2-pen tenoic and itaconic acids regardless of whether the deuterium source was D- 2 or D2O. Itaconic acid was deuterated up to 3.6 D/methylsuccinic acid. Det ailed H-1- and C-13-NMR studies identified six isotopomers of the deuterate d methylsuccinic acid product and revealed an important role of the H/D exc hange on the catalytically active Pd-intermediate.