Synthesis of 2-phenyl-1,3-oxazepine by the irradiation of 4-phenyl-2,3-oxazabicyclo[3.2.0]Hepta-3,6-diene

✍ Scribed by T. Mukai; H. Sukawa

• Publisher: Elsevier Science
• Year: 1973
• Tongue: French
• Weight: 234 KB
• Volume: 14
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)96252-5

✦ Synopsis

It is well known that 1,3-oxazepine derivatives are formed by the irradiation of aromatic amine N-oxides (2), but in the case of monocyclic system the isolation of the 1,3-oxazepines is rather exceptional (3,4), and they usually exist as transient intermediates (5). However, we found that the irradiation of 4-phenyl-2,5oxazabicyclo[3.2.0]hepta-5,6-diene (I) (6) afforded easily 2-phenyl-l,3-oxazepine (II) in high yields. Therefore this procedure is a valuable method for the synthesis of the monocyclic 1,3-oxazepines. In addition, this is probably the first example of the formation of heteropines by the irradiation of bicyclo[3.2.0]heptadienes with two heteroatoms. We wish to describe here preliminary results obtained and our interpretation of the the reaction mechanism for the formation of II.