Jm. Humphrey et al., EFFICIENT SYNTHESIS OF DIASTEREOSELECTIVELY LABELED (3S)-[4-C-13]-L-VALINE, AND REGIOSELECTIVELY LABELED [3-(CH3)-C-13]-L-ISOLEUCINE HYDROCHLORIDES, Bioorganic & medicinal chemistry letters, 5(12), 1995, pp. 1315-1320
Diastereoselectively labeled (3S)-[4-C-13]-L valine and regioselective
ly labeled [3-(CH3)-C-13]-L-isoleucine hydrochlorides were synthesized
in 54% and 62% respective overall yields from L-aspartic acid.