N-Boc-D-aspartic Acid 1-tert-Butyl Ester is used in the preparation of optically pure fluoroglutamines and their 18F-labeled derivatives as metabolic imaging agents for tumors. It is also used to synthesize 4-methoxy-7-nitroindolinyl-D-aspartate, a photolabile caged compd. for selective activation of glutamate transporters and N-Me-D-aspartate receptors in brain tissue.