An efficient and diastereoselective synthetic method for preparing (E)-3-styrylchromones has been developed by the reaction of chromone-3-carboxaldehyde with phenylacetic acids in the presence of potassium tert-butoxide under classical heating conditions or microwave irradiation. The Knoevenagel-type reaction followed by a decarboxylation was faster under microwave conditions.
A Brønsted acid controlled Diels-Alder reaction of 3-vinylchromones with arynes has been developed. By employing different kinds and amounts of acid, 9-aryl-9H-xanthen-9-ols or ortho-hydroxybenzophenones could be controllably furnished in good yields in an atom- and step-economic manner.
Novel (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles from (E)- and (Z)-3-styrylchromones: the unexpected case of (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles
作者:Vera L.M. Silva、Artur M.S. Silva、Diana C.G.A. Pinto、José A.S. Cavaleiro、José Elguero
DOI:10.1016/j.tetlet.2007.03.147
日期:2007.5
An efficient synthetic method for the preparation of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles has been developed. The reaction of (E)- and (Z)-3-styrylchromones with hydrazine hydrate afforded the corresponding (E)- and (Z)-4-styrylpyrazoles, respectively, saved 4′-nitro-derivatives where both (E)- and (Z)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles
Synthesis of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles
作者:Vera L. M. Silva、Artur M. S. Silva、Diana C. G. A. Pinto、José A. S. Cavaleiro、José Elguero
DOI:10.1007/s00706-008-0002-9
日期:2009.1
AbstractAn efficient synthesis method for the preparation of a series of new (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles was developed. The reaction of (Z)- and (E)-3-styrylchromones with hydrazine hydrate afforded the corresponding (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles, except for nitro derivatives, where both (Z)- and (E)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyph
Electron-Deficient Dienes. 5. An Inverse-Electron-Demand Diels−Alder Approach to 2-Substituted 4-Methoxyxanthones and 3,4-Dimethoxyxanthones
作者:Anh-Thu Dang、David O. Miller、Louise N. Dawe、Graham J. Bodwell
DOI:10.1021/ol702614b
日期:2008.1.1
Several 4-methoxyxanthones and 3,4-dimethoxyxanthones were synthesized in good yield via inverse-electron-demand Diels-Alder (IEDDA) driven domino reactions between a series of electron-deficient chromone-fused dienes with 1-(2,2-dimethoxyvinyl)pyrrolidine or tetramethoxyethene, respectively.