Vicinal di-functionalization of α,β-unsaturated ketones via manganese carbene intermediates: synthesis of γ-acyl-δ-lactones by cascade Michael addition/aldol/transesterification reactions

✍ Scribed by Carole Mongin; Karin Gruet; Noël Lugan; René Mathieu

• Book ID: 104210799
• Publisher: Elsevier Science
• Year: 2000
• Tongue: French
• Weight: 132 KB
• Volume: 41
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)01234-x

✦ Synopsis

The carbene±enolate complexes generated upon reaction of the carbene anion [Cp H (CO) 2 MnC(OEt)CH 2 ] ŵith benzylidene acetone and chalcone react with benzaldehyde to form the 6-membered oxacyclocarbene complexes Cp H (CO) 2 MnCCH 2 CH(Ph)CH(C{O}R)CH(Ph)O (R=Me, Ph). The latter, which can be regarded as the result of cascade Michael addition/aldol/transesteri®cation reactions, are readily oxidized by air to release the corresponding g-acyl-d-lactones.