Acid-catalyzed convenient transformation of 1-aryl-2-pentene-1,4-diones into polyfunctionalized furans

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• 作者：Onitsuka ; Satoaki ; Nishino ; Hiroshi ; Kurosawa ; Kazu
• 关键词：tri-substituted furans ; tetra-substituted furans ; 1 ; 4-diketones ; boron trifluoride
• 刊名：Tetrahedron Letters
• 出版年：2000
• 出版时间：April 22, 2000
• 年：2000
• 卷：41
• 期：17
• 页码：3149-3152
• 全文大小：140 K

文摘

The reaction of phenylglyoxal with 2,4-pentanedione in the presence of boron trifluoride gave the unstable 3-acetyl-1-phenyl-2-pentene-1,4-dione intermediate which was converted in situ by the reaction with an excess amount of 2,4-pentanedione into new crystalline tri- and tetra-substituted furans. Other unstable 1-aryl-2-pentene-1,4-diones, which were obtained by the photooxygenation of 3-acetyl-5-aryl-2-methylfurans, were trapped by the acid-catalyzed reaction, giving polyfunctionalized furans in good yields. Treatment of the 1-phenyl-2-pentene-1,4-dione intermediate with concentrated hydrochloric acid followed by boiling ethanol quantitatively yielded a stable 2-ethoxymethylfuran via the unstable 2-chloromethylfuran.