作者:L. Jurd
DOI:10.1016/0040-4020(75)80304-8
日期:1975.1
Flavylium salts and 2-hydroxychalcones (1-phenyl-3-(2-hydroxyphenyl)-2-propen-1-ones) react with hydroxylamine in pyridine to form 2,5-dihydroisoxazoles. These undergo thermal and acid-catalyzed rearrangements to isomeric 4,5-dihydroisoxazoles and chalcone oximes, respectively. With hydrazine, flavylium salts yield phenolic 4,5-dihydro-3,5-diphenyl-1H-pyrazoles. Since these readily condense with acetone
黄酮盐和2-羟基查耳酮(1-苯基-3-(2-羟基苯基)-2-丙烯-1-酮)与吡啶中的羟胺反应形成2,5-二氢异恶唑。它们分别进行热和酸催化重排,分别形成异构体4,5-二氢异恶唑和查尔酮肟。黄酮盐与肼一起产生酚类4,5-二氢-3,5-二苯基-1H-吡唑。由于这些很容易与丙酮缩合形成环丙酮化物,因此酰化反应涉及在黄酮核的2位发生最初的亲核攻击。