Synthesis of О-2-(acyl)vinylketoximes and their unusual rearrangements into 2- and 3-acyl-substituted pyrroles

✍ Scribed by Tatyana E. Glotova; Elena Yu. Schmidt; Marina Yu. Dvorko; Igor’ A. Ushakov; Al’bina I. Mikhaleva; Boris A. Trofimov

• Publisher: Elsevier Science
• Year: 2010
• Tongue: French
• Weight: 489 KB
• Volume: 51
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2010.09.101

✦ Synopsis

O-2-(Acyl)vinylketoximes (freshly prepared from ketoximes and acylacetylenes in the presence of Ph 3 P as catalyst in up to 83% yields) rearrange upon heating (125-150 °C) to give 2-or 3-acylpyrroles, wherein the positions of the acyl substituents do not correspond to known O-vinyloxime rearrangements; the chemo-and regioselectivity of the rearrangements depend on the reaction conditions. The described rearrangement enables syntheses of previously inaccessible substituted 2-or 3-acylpyrroles.