Using easily accessible aromatic alkoxy-arylalkynones, we have investigated the gold-catalyzed intramolecular addition of ethers to alkynes, to give easy access to various substitutedchromones. This reaction involves the transfer of the ether substituent via a carbodemetallation process. We also noticed a competing isomerization of several starting materials for which we propose a second gold catalyzed
Tandem Claisen Rearrangement/6-<i>endo</i>Cyclization Approach to Allylated and Prenylated Chromones
作者:Bernd Schmidt、Martin Riemer、Uwe Schilde
DOI:10.1002/ejoc.201501151
日期:2015.12
o-acylphenols reacted upon microwave irradiation to form C-allylated or -prenylated chromone derivatives, depending on the substitution pattern of the arene and the allyl substituent. The reaction proceeds through a tandemClaisen rearrangement and 6-endo-trig or 6-endo-dig cyclization sequence. For prenyl ethers, the tandem sequence can be extended by a Cope rearrangement to furnish 6-prenylchromones.