Synthesis of [1-13C]pyruvic acid], [2-13C]pyruvic acid], [3-13C]pyruvic acid] and combinations thereof

The present invention is directed to the labeled compounds, wherein C* is each either 13C and 12C where at least one C* is 13C, each hydrogen of the methylene group is hydrogen or deuterium, the methyl group includes either zero or three deuterium atoms, Q is sulfide, sulfinyl, or sulfone, Z is an aryl group such as 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, or a phenyl group wherein R1, R2, R3, R4 and R5 are each independently either hydrogen, a C1-C4 lower alkyl, a halogen, and an amino group such as NH2, NHR and NRR′ where R and R′ are each independently either a C1-C4 lower alkyl, a phenyl, and an alkoxy group, and the methyl group can include either zero or three deuterium atoms. The present invention is also directed to the labeled compounds