2-(1-Methyl-1H-2-benzopyran-3-yl)-α-diazoacetophenone | 166756-95-2

• 分子结构分类: 有机化合物 - 苯类化合物 - 茚和异茚
• 英文名称: 2-(1-Methyl-1H-2-benzopyran-3-yl)-α-diazoacetophenone
• 英文别名: 2-diazo-1-[2-(1-methyl-1H-isochromen-3-yl)phenyl]ethanone
• CAS: 166756-95-2
• 化学式: C₁₈H₁₄N₂O₂
• 分子量: 290.321
• InChiKey: KOWDNCHDIKZSFG-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.7
• 重原子数：
  22
• 可旋转键数：
  3
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.11
• 拓扑面积：
  28.3
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  2-(1-Methyl-1H-2-benzopyran-3-yl)-α-diazoacetophenone 在 Rh2[(+/-)-mandelate]4 作用下， 以 二氯甲烷 为溶剂， 反应 16.0h， 以73%的产率得到11,12-Dihydro-6,12-epoxy-13-methyl-13H-dibenzocyclononen-11-one
  参考文献：
  名称：

  An Unusual Example of a 6-Endo-Dig Addition to an Unactivated Carbon-Carbon Triple Bond

  摘要：

  Methyl 2-[2-[2-(1-hydroxy-1-ethyl)phenyl]ethynyl]benzoate was prepared as an intermediate for subsequent conversion to an a-diazo ketone. Under the basic conditions used to hydrolyze the methyl ester, the neighboring hydroxyl functionality underwent reaction with the unactivated acetylenic group, producing a benzopyranyl-substituted alpha-diazoacetophenone. Treatment of this diazocarbonyl compound with a catalytic quantity of rhodium(II) mandelate afforded a novel dibenzo[a,e]cyclononenone derivative. The reaction proceeds via an initially formed oxonium ylide which rearranges further by means of a 1,2-alkyl shift. A prime factor in determining the direction of internal cyclization to the triple bond is the presence of the carbomethoxy group in the ortho position of the beta-phenyl ring. Thus, in contrast with related systems which exhibit a clear preference for 5-exo-dig cyclization at the acetylenic center, the 6-endo-dig addition is the preferred pathway for the o-formyl- and o-carbomethoxy-substituted alkynyl alcohols. Careful monitoring of the reaction actually showed that the reaction proceeds by initial formation of the 5-exo-dig product followed by a novel rearrangement to the 6-endo product.

  DOI：

  10.1021/jo00122a047
• 作为产物：
  描述：

  2-[(三甲基硅基)乙炔基]苯甲醛 在 氢氧化钾 、 copper(l) iodide 、 bis(triphenylphosphine)palladium(II)-chloride 、 草酰氯 、 四丁基氟化铵 、 甲基锂 、 三乙胺 、 N,N-二甲基甲酰胺 作用下， 以 四氢呋喃 、 甲醇 、 乙醚 、 水 为溶剂， 反应 57.0h， 生成 2-(1-Methyl-1H-2-benzopyran-3-yl)-α-diazoacetophenone
  参考文献：
  名称：

  An Unusual Example of a 6-Endo-Dig Addition to an Unactivated Carbon-Carbon Triple Bond

  摘要：

  Methyl 2-[2-[2-(1-hydroxy-1-ethyl)phenyl]ethynyl]benzoate was prepared as an intermediate for subsequent conversion to an a-diazo ketone. Under the basic conditions used to hydrolyze the methyl ester, the neighboring hydroxyl functionality underwent reaction with the unactivated acetylenic group, producing a benzopyranyl-substituted alpha-diazoacetophenone. Treatment of this diazocarbonyl compound with a catalytic quantity of rhodium(II) mandelate afforded a novel dibenzo[a,e]cyclononenone derivative. The reaction proceeds via an initially formed oxonium ylide which rearranges further by means of a 1,2-alkyl shift. A prime factor in determining the direction of internal cyclization to the triple bond is the presence of the carbomethoxy group in the ortho position of the beta-phenyl ring. Thus, in contrast with related systems which exhibit a clear preference for 5-exo-dig cyclization at the acetylenic center, the 6-endo-dig addition is the preferred pathway for the o-formyl- and o-carbomethoxy-substituted alkynyl alcohols. Careful monitoring of the reaction actually showed that the reaction proceeds by initial formation of the 5-exo-dig product followed by a novel rearrangement to the 6-endo product.

  DOI：

  10.1021/jo00122a047