An asymmetric synthesis of L-[2-C-13]aspartic acid from sodium [2-C-13]acetate

L-[2-C-13]Aspartic acid was synthesized by using Dellaria's oxazinone label led with C-13 at the 3-position, prepared from phenyl [2-C-13]bromoacetate and (S)-2-phenylglycinol, as a chiral glycine equivalent. Phenyl [2-C-13]br omoacetate was derived from sodium [2-C-13]acetate. Alkylation of the [3-C- 13]oxazinone with ethyl bromoacetate was achieved with high diastereoselect ivity. Finally, sequential deprotection and removal of the chiral auxiliary of the alkylated [3-C-13]oxazinone afforded L-[2-C-13]aspartic acid.