Deuterated amino acids. IV. The synthesis of L-phenyl d₅-alanine-2,3,3-d₃

The synthesis of L-phenyl-d₅-alanine-2,3,3-d₃ is described. The synthetic route involved the enzymatic deacylation of acetylphenyl-d₅-alanine-2,3,3-d₃, which was obtained by catalytic reduction (deuteriumation) of the hydrolyzed 2-methyl oxazolone derivative of benzaldehyde-d₆. The ultraviolet, infrared, and optical rotatory dispersion spectra of L-phenylalanine-d₈ are reported along with some corresponding data on the deuterated intermediates.