Ring opening and ring closure reactions of chromone-3-carboxylic acid: unexpected routes to synthesize functionalized benzoxocinones and heteroannulated pyranochromenes

Authors : Magdy Ahmed Ibrahim, Tarik El-sayed Ali

Pages : 412-0

Doi:10.3906/kim-1410-41

View : 27 | Download : 12

Publication Date : 9999-12-31

Article Type : Makaleler

Abstract :Unexpected routes to synthesize functionalized benzoxocinones and heteroannulated pyranochromenes were achieved via transformations of the \gamma-pyrone ring in chromone-3-carboxylic acid throughout its reactions with some acyclic and cyclic carbon nucleophiles. A key part of the reaction mechanisms is discussed. Structures of the new synthesized products were established on the basis of elemental analysis and spectral data (IR, MS, and ^1H and ^{13}C NMR).
Keywords : Chromone-3-carboxylic acid, benzoxocinone, pyranochromenes, ring expansion, carbon nucleophiles