Useful synthetic building block, e.g. in an oxazole synthesis: J. Med. Chem., 36, 3871 (1993). Formation of amides has been used in the syntheses of 1,2,4-triazine-3,6-diones, and of a vicinal tricarbonyl amide derivative of L-phenylalanine: J. Org. Chem., 60, 5992 (1995); 61, 1872 (1996).