Synthesis of pyranones, substituted furfurals and pyrroles via oxidative rearrangement

ORGN 872

Ann Rowley Kelly, annkelly@sas.upenn.edu, Michael H. Kerrigan, mhkerrig@sas.upenn.edu, Rachel Kohn, Jessica Dweck, jdweck@sas.upenn.edu, Alice E. Lurain, alurain@sas.upenn.edu, and Patrick J. Walsh, pwalsh@sas.upenn.edu. Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, PA 19104
In this report, we discuss a one pot method for the synthesis of pyranones from 2-furfurals. The sequence begins with a catalytic asymmetric addition of a dialkylzinc reagent to a furfural followed by a subsequent oxidation with N-bromosuccidimide. High enantioselectivities and good yields were obtained for this tandem sequence. Synthesis of 2-substitued 3-furfurals by ortho metallation reactions has proved challenging, resulting in formation of a mixture of products. We have found that addition of alkyl and aryl organometallic reagents to the furfural followed by oxidation and elimination gives the substituted furfural in good yields. A variety of alkyl and aryl groups have been employed. 2-Substituted 3- carboxy pyrroles have also been generated from the imine derivatives.

 

Heterocycles and Aromatics
8:00 AM-12:00 PM, Thursday, 14 September 2006 Moscone Center -- Room 135, Oral

Division of Organic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006