Cation radical [4 + 3] cycloadditions

ORGN 327

Desmond H. Murray, murrayd@andrews.edu, Department of Chemistry and Biochemistry, Andrews University, Berrien Springs, MI 49104
We report here the discovery of an unprecedented oxidative cycloaddition reaction as part of our ongoing systematic research into the novel chemistry of densely functionalized organic molecules. In this instance, we were investigating the latent ambiphilic reactivity of alpha-ketoacetal enol silanes as a synthetic route to oxygenated seven-membered rings. To our knowledge, the reaction described here is a new type of single electron transfer, cation radical cycloaddition. It is initiated stoichiometrically by organic oxidants or catalytically by inorganic oxidants. A possible mechanism is proposed for this reaction that offers several advantages as an alternative to ‘normal' Lewis acid catalyzed [4 + 3] cycloadditions.
 

New Reactions and Methodology
8:15 AM-11:55 AM, Tuesday, March 27, 2007 McCormick Place Lakeside -- Room E351, Level 3, Oral

Division of Organic Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007