3-Methyl-2-cyclopentenone 1,2-Ethanediyl Acetal | 82222-82-0

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 3-Methyl-2-cyclopentenone 1,2-Ethanediyl Acetal
• 英文别名: 8-methyl-1,4-dioxaspiro[4.4]non-8-ene
• CAS: 82222-82-0
• 化学式: C₈H₁₂O₂
• 分子量: 140.182
• InChiKey: IPNFSUPBXZIWCP-UHFFFAOYSA-N

物化性质

• 沸点：
  47 °C(Press: 4.5 Torr)
• 密度：
  1.08±0.1 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  1.47
• 重原子数：
  10.0
• 可旋转键数：
  0.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.75
• 拓扑面积：
  18.46
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为反应物：
  描述：

  3-Methyl-2-cyclopentenone 1,2-Ethanediyl Acetal 在 溶剂黄146 作用下， 以 乙腈 为溶剂， 反应 48.0h， 生成 (1S,4S)-1-Methyl-5-oxo-bicyclo[2.2.1]hept-2-ene-2,3-dicarboxylic acid dimethyl ester
  参考文献：
  名称：

  A one-step synthesis of 2-norbornanone ethylene acetals from 2-cyclopenten-1-one ethylene acetals and dienophiles via [2 + 4] cycloaddition of in situ generated 2-(2-hydroxyethoxy)cyclopenta-1,3-dienes and intramolecular reacetalization

  摘要：

  2-(2-Hydroxyethoxy)cyclopenta-1,3-diene (5) which is generated reversibly from 2-cyclopenten-1-one ethylene acetal (1) under mild, neutral conditions can be intercepted with a variety of dienophiles ultimately to give 2-norbornanone ethylene acetals in 62-100% yields. The addition reactions are highly stereo- and regioselective. Of the several solvents examined, acetonitrile is the most satisfactory. In CHCl3 or CCl4, decomposition of 1 is induced, leading to diminished yields of the adducts. The intermediate 5 is detected by UV spectroscopy, and its content relative to 1 at a stationary state at 70-degrees-C in acetonitrile is estimated to be ca. 0.2%. The reactions of the 2-, 3-, and 5-methyl-substituted derivatives 2-4 with dienophiles similarly led to the production of the corresponding 2-norbornanone acetals through the additions of the dienophiles to the 1,3-cyclopentadien-2-yl ether intermediates 6-8 selectively derived from 2-4 via 1,2-elimination. The formation of isomeric adducts resulting either from 1,4-elimination in 1-4 or from [1,51 hydrogen migration in the enol ether intermediates is not detected. The addition of 2-chloroacrylonitrile, a ketene equivalent, to 1-4 followed by alkaline hydrolysis provides singly acetalized 2,5-norbornadiones in two steps in good yields. 2-Cyclohexen-1-one ethylene acetal (44) also undergoes the addition of dienophiles in the [2 + 4] manner directly to give bicyclo[2.2.2]octan-2-one ethylene acetals, but is substantially less reactive than 1 toward this type of reaction.

  DOI：

  10.1021/jo00071a033
• 作为产物：
  描述：

  3-Methyl-3-tosylcyclopentanone 1,2-Ethanediyl Acetal 在 正丁基锂 作用下， 以 四氢呋喃 、 正己烷 为溶剂， 反应 0.5h， 以91%的产率得到3-Methyl-2-cyclopentenone 1,2-Ethanediyl Acetal
  参考文献：
  名称：

  3-Methyl-2-cyclopentenone-Derived Synthons

  摘要：

  DOI：

  10.1055/s-1982-29807

文献信息

• Studies toward the Total Syntheses of Cucurbitacins B and D
  作者：Michael E. Jung、Rebecca M. Lui

  DOI：10.1021/jo101242e

  日期：2010.11.5

  Synthetic efforts toward the convergent construction of the tetracyclic triterpenoids cucurbitacins B and D are described. The results of a Diels−Alder study examining the effects of steric and electronic variations of 2-methyl-2-cyclohexenone on the endo/exo-diastereoselectivity of the reaction are presented. The diastereomer of the core of the cucurbitacins, epimeric at C8, C9, and C10, 51, was synthesized

  描述了对四环三萜类葫芦素B和D的收敛构建的合成努力。提出了Diels-Alder研究的结果，该研究检查了2-甲基-2-环己烯酮的空间和电子变化对反应的内/外-非对映选择性的影响。的葫芦素，差向异构的C8，C9和C10，的芯的非对映体51，经由二烯的高度区域选择性和立体选择性的Diels-Alder反应来合成4和新的亲二烯体50。