The photo-Fires rearrangement. A mild and convenient photochemical method for the síntesis of 4-pyranones and 4-quinolones.

M. BONESI, SERGIO; ERRA BALSELLS, ROSA

Bahia de San Salvador, Brasil.

Congreso; I-APS, Bahia de San Salvador, Brasil, junio 12-16, 2006; 2006

Inter-American Photochemical Society.

The photo Fries rearrangement has received considerable attention since its discovery in 1960 by Anderson and Reese, and the studies have been devoted mainly to elucidating the mechanism of the reaction rather than its use in synthesis. However, this photochemical reaction has been successfully used in the synthesis of natural products such as griseofulvin, daunomycine and flavonoids. It is known that the photo Fries rearrangement takes place in mild conditions giving o-hydroxyketone or o-aminoketone derivatives in good chemical yields. These intermediates are interesting synthons for the synthesis of a variety of natural products that contains in their structure a 4-pyranone or 4-quinolone moiety. In this communication we report the photochemical studies of aromatic ester and amide derivatives shown in Scheme I. Several compounds have been synthesized for the first time and have been characterized by means of physical and spectroscopic methods (mp, MS, IR, NMR).