An Expedient Route to the Tetrazole Analogues of α-Amino Acids

[reaction: see text] Convenient conditions are described for the transformation of alpha-aminonitriles to the tetrazole analogues of alpha-amino acids. Refluxing the starting material in water/2-propanol at 80 degrees C with sodium azide and catalytic zinc bromide affords the tetrazole product in yields generally exceeding 90%.