Evaluation of N-hydroxymethylphthalimide in alkaline medium: Novel entry to the tricyclic [1,3]oxazepine core via an intramolecular π and O-cationic cyclization

✍ Scribed by Armelle Cul; Anthony Pesquet; Adam Daïch; Abderrahim Chihab-Eddine; Štefan Marchalín

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2003
• Tongue: English
• Weight: 119 KB
• Volume: 40
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570400314

✦ Synopsis

Abstract

Fused isoindolo[1,3]benzo(or thieno)oxazepines 8a,b and one of their positional isomers aromatic tricyclic N,O‐acetals 13b are reported to occur efficiently in a three‐step sequence from N‐hydroxy‐methylphthalimide (6). The key step of this methodology is the intramolecular arylation of an endocyclic and/or exocyclic N‐acyliminium cation. The mechanism leading to these species, in particular to a tricyclic lactam 13b, is discussed.