4,4-dimethyl-3,4,5,6-tetrahydro-2H-cyclopenta[b]pyran-7-one

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 4,4-dimethyl-3,4,5,6-tetrahydro-2H-cyclopenta[b]pyran-7-one
• 英文别名: 4,4,5-Trimethyl-2,3,5,6-tetrahydrocyclopenta[b]pyran-7-one
• 化学式: C₁₁H₁₆O₂
• 分子量: 180.247
• InChiKey: BLUHGDWRPRIGMM-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.9
• 重原子数：
  13
• 可旋转键数：
  0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.73
• 拓扑面积：
  26.3
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  4,4-dimethyl-tetrahydro-pyran-2-one 在 六甲基磷酰三胺 、 bis-triphenylphosphine-palladium(II) chloride 、 Amberlyst 15 、 potassium carbonate 、 lithium hexamethyldisilazane 作用下， 以 四氢呋喃 、 二氯甲烷 为溶剂， 反应 5.0h， 生成 4,4-dimethyl-3,4,5,6-tetrahydro-2H-cyclopenta[b]pyran-7-one
  参考文献：
  名称：

  New Synthetic Approach to Cyclopenta-Fused Heterocycles Based upon a Mild Nazarov Reaction. 2. Further Studies on the Torquoselectivity

  摘要：

  Conjugated alkoxytrienes in which one of the double bonds is embedded in a heterocyclic moiety are obtained by the Pd-catalyzed coupling reaction of lactam- and lactone-derived vinyl triflates with alpha-alkoxydienylboronates. These compounds undergo a 4pi electrocyclization process (Nazarov reaction) under acidic conditions and afford cyclopenta-fused heterocycles in good yields. As a continuation of a previous study, the torquoselectivity of this Nazarov reaction has been investigated using 2-alkyl-substituted pyrrolidinone and 2- and 4-substituted delta-valerolactone derivatives. High or complete stereoselectivity has only been observed with the 2-alkyl-substituted heterocycles. Both steric and stereoelectronic effects could contribute to determining the stereoselection of the ring closure.

  DOI：

  10.1021/jo0489263

文献信息

• Stereoselective Synthesis of Spirocyclic Ketones by Nazarov Reaction
  作者：Cristina Prandi、Annamaria Deagostino、Paolo Venturello、Ernesto G. Occhiato

  DOI：10.1021/ol051464a

  日期：2005.9.1

  [reaction: see text] The Suzuki-Miyaura cross-coupling reaction between alpha-ethoxydienyl boronates and lactone-derived vinyl triflates affords functionalized 6-(1-ethoxy-1,3-butadienyl)dihydropyran derivatives that undergo a Nazarov electrocyclic reaction under mild acidic conditions to give functionalized spirocyclic ketones. The product distribution and the stereoselectivity of the process are

  [反应：参见文本]α-乙氧基二烯基硼酸酯与内酯衍生的乙烯基三氟甲磺酸酯之间的Suzuki-Miyaura交叉偶联反应提供了功能化的6-（1-乙氧基-1,3-丁二烯基）二氢吡喃衍生物，该衍生物在温和的条件下进行了Nazarov环化反应在酸性条件下得到官能化的螺环酮。该方法的产物分布和立体选择性强烈取决于α-乙氧基二烯和二氢吡喃部分的取代。在二氢吡喃部分上存在C 2-取代基时，观察到高的立体选择性。根据过渡态的几何形状解释了结果。