Dibenzoylfuroxan (3) under bar (R = Ph) reacts with hydroxylamine in a ring
transformation to give a 4,5-dioximino-3-phenyl-1,2-oxazole (6) under bar.
The structure of (6) under bar has been confirmed by an X-ray structure de
termination. Some density functional theoretical (DFT) calculations for (6)
under bar and related compounds are reported.