DL-Malic Acid-2,3,3-d3 is used in the synthesis of certain deuterated organic compounds for spectroscopic studies. Also, an isotope labelled compound of DL-Malic Acid (M159510), which the naturally occuring isomer is the L-form which has been found in apples and many other fruits and plants. Selective α-amino protecting reagent for amino acid derivatives. Versatile synthon for the preparation of chiral compounds including κ-opioid receptor agonists, 1α,25-dihydroxyvitamin D3 analogue, and phoslactomycin B.