HEXACARBONYLMOLYBDENUM- OR NONACARBONYLDIIRON-INDUCED REACTION OF 1,3-OXAZEPINE RING SYSTEM. EVIDENCE FOR THE VALENCE ISOMERIZATION BETWEEN 1,3-OXAZEPINE AND PYRIDINE-2,3-OXIDE
Upon treatment with [Mo(CO)6] or [Fe2(CO)9], phenyl-substituted 1,3-oxazepines undergo the C-2-O and C-7-O bond cleavage to give pyridine and pyrrole derivatives via a coordinated pyridine-2,3-oxide.