17-ethoxycarbonyl-11,23-dimethyl-5-nitro-25,26,27,28-tetrahydroxycalix[4]arene | 133871-42-8

• 分子结构分类: 有机化合物 - 有机1,3-偶极化合物 - 烯丙基型1,3-偶极有机化合物
• 英文名称: 17-ethoxycarbonyl-11,23-dimethyl-5-nitro-25,26,27,28-tetrahydroxycalix[4]arene
• 英文别名: Ethyl 25,26,27,28-tetrahydroxy-11,23-dimethyl-17-nitropentacyclo[19.3.1.13,7.19,13.115,19]octacosa-1(25),3,5,7(28),9(27),10,12,15(26),16,18,21,23-dodecaene-5-carboxylate
• CAS: 133871-42-8
• 化学式: C₃₃H₃₁NO₈
• 分子量: 569.611
• InChiKey: OBACWGOXKQAWNK-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  7
• 重原子数：
  42
• 可旋转键数：
  3
• 环数：
  5.0
• sp3杂化的碳原子比例：
  0.24
• 拓扑面积：
  153
• 氢给体数：
  4
• 氢受体数：
  8

反应信息

• 作为反应物：
  描述：

  17-ethoxycarbonyl-11,23-dimethyl-5-nitro-25,26,27,28-tetrahydroxycalix[4]arene 在 sodium hydroxide 、 对甲苯磺酸 作用下， 以 乙醇 、 水 为溶剂， 反应 40.0h， 生成 25,26,27,28,tetraacetoxy-5-carboxy-11,23-dimethyl-17-nitrocalix<4>arene
  参考文献：
  名称：

  Carbon-13 NMR chemical shifts. A single rule to determine the conformation of calix[4]arenes

  摘要：

  The conformations of calix[4]arenes can be deduced from the C-13 NMR chemical shift of the methylene groups connecting each pair of aromatic rings. Inspection of 24 cases revealed that when the phenol rings beside each methylene are in a syn orientation (i.e., in cone conformations), the methylene signals appear around delta 31, whereas they appear around delta 37 when both phenol rings are anti oriented (i.e., in 1,3-alternate conformations). Steric effects are believed to be the main cause of such large differences.

  DOI：

  10.1021/jo00010a036
• 作为产物：
  描述：

  2,6-二(羟甲基)-4-硝基苯酚 在 四氯化钛 作用下， 以 1,4-二氧六环 为溶剂， 反应 152.0h， 生成 17-ethoxycarbonyl-11,23-dimethyl-5-nitro-25,26,27,28-tetrahydroxycalix[4]arene
  参考文献：
  名称：

  Carbon-13 NMR chemical shifts. A single rule to determine the conformation of calix[4]arenes

  摘要：

  The conformations of calix[4]arenes can be deduced from the C-13 NMR chemical shift of the methylene groups connecting each pair of aromatic rings. Inspection of 24 cases revealed that when the phenol rings beside each methylene are in a syn orientation (i.e., in cone conformations), the methylene signals appear around delta 31, whereas they appear around delta 37 when both phenol rings are anti oriented (i.e., in 1,3-alternate conformations). Steric effects are believed to be the main cause of such large differences.

  DOI：

  10.1021/jo00010a036

文献信息

• The first acid constant of calix[4]arenes
  作者：Michaela Backes、Volker Böhmer、George Ferguson、Cordula Grüttner、Christian Schmidt、Walter Vogt、Kadija Ziat

  DOI：10.1039/a607259c

  日期：——

  A series of calix[4]arenes containing a single p-nitrophenol unit (or two p-nitrophenol units) have been synthesized by fragment condensation. Their first acid constant (pKa1) has been determined in 2-methoxyethanol–water (9:1) by optical titration. Relative to the corresponding linear trimers with a p-nitrophenol in the middle, a decrease of pKa1 by 2.1 units or more is observed, which can be explained entirely by intramolecular hydrogen bonds stabilising the monoanion. In this way electron-withdrawing p-substituents in the opposite phenolic unit lead to a further decrease in pKa1, while a distortion of the cone conformation by m-methyl groups causes a slight increase. The structure of one calix[4]arene was further confirmed by single crystal X-ray analysis showing the molecule in the usual cone conformation.

  通过片段缩合法合成了一系列含有一个对硝基苯酚单元（或两个对硝基苯酚单元）的钙[4]炔。通过光学滴定法测定了它们在 2-甲氧基乙醇-水（9:1）中的第一酸常数（pKa1）。 与中间含有一个对硝基苯酚的相应线性三聚体相比，pKa1 下降了 2.1 个单位或更多，这完全可以用稳定单阴离子的分子内氢键来解释。这样，相反的酚单元中的抽电子 p 取代基会导致 pKa1 进一步降低，而 m-甲基基团对锥形构象的扭曲则会导致 pKa1 略微升高。单晶 X 射线分析进一步证实了一种钙[4]炔的结构，显示该分子呈通常的锥形构象。
• Carbon-13 NMR chemical shifts. A single rule to determine the conformation of calix[4]arenes
  作者：Carlos Jaime、Javier De Mendoza、Pilar Prados、Pedro M. Nieto、Concha Sanchez

  DOI：10.1021/jo00010a036

  日期：1991.5

  The conformations of calix[4]arenes can be deduced from the C-13 NMR chemical shift of the methylene groups connecting each pair of aromatic rings. Inspection of 24 cases revealed that when the phenol rings beside each methylene are in a syn orientation (i.e., in cone conformations), the methylene signals appear around delta 31, whereas they appear around delta 37 when both phenol rings are anti oriented (i.e., in 1,3-alternate conformations). Steric effects are believed to be the main cause of such large differences.