the Beckmann fragmentation of alpha-alkoxy and alpha-alkoxy-alpha-alkyl oxime acetates have been successfully trapped as phosphonium salts, which were subsequently reacted with a variety of Grignard reagents to give the corresponding substituted products in good yields. Notably, this reaction proceeded smoothly even from alpha-alkoxy-alpha-alkyl oxime acetates.
Cation−n Control of Regiochemistry of Intramolecular Schmidt Reactions en Route to Bridged Bicyclic Lactams
作者:Michal Szostak、Lei Yao、Jeffrey Aubé
DOI:10.1021/ol901771b
日期:2009.10.1
The regiochemistry of the intramolecular Schmidt reaction of 2-azidoalkylketones is controlled by placing a thioether substituent at the position adjacent to the ketone to provide access to a family of unsubstituted medium bridged twisted amides. This outcome is ascribed to the presence of stabilizing through-space interactions between the diazonium cation and the n electrons on heteroatom and does