Tetrahedron

Reactions of 3-(polyfluoroacyl) chromones with hydroxylamine: synthesis of novel R F-containing isoxazole and chromone derivatives

VY Sosnovskikh, VS Moshkin, MI Kodess

Index: Sosnovskikh, Vyacheslav Ya.; Moshkin, Vladimir S.; Kodess, Mikhail I. Tetrahedron, 2008 , vol. 64, # 34 p. 7877 - 7889

Full Text: HTML

Citation Number: 40

Abstract

Reaction of 3-(polyfluoroacyl) chromones with hydroxylamine free base proceeds via nucleophilic 1, 4-addition followed by opening of the pyrone ring and subsequent cyclization to 4-(polyfluoroalkyl)-4H-chromeno [3, 4-d] isoxazol-4-ols in good yields. On treatment with trifluoroacetic acid, the isoxazole ring of this annulated heterocyclic system opens to give 3- cyano-2-(polyfluoroalkyl) chromones, which were successfully hydrolyzed with ...