2,2-Bis-pentamethylphenyl-ethene-1,1-diol | 112752-36-0

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 异戊烯醇脂质
• 英文名称: 2,2-Bis-pentamethylphenyl-ethene-1,1-diol
• 英文别名: 1,1-Ethenediol, 2,2-bis(pentamethylphenyl)-；2,2-bis(2,3,4,5,6-pentamethylphenyl)ethene-1,1-diol
• CAS: 112752-36-0
• 化学式: C₂₄H₃₂O₂
• 分子量: 352.517
• InChiKey: LMNVWIAGFVQRID-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  7.4
• 重原子数：
  26
• 可旋转键数：
  2
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.42
• 拓扑面积：
  40.5
• 氢给体数：
  2
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  2,2-Bis-pentamethylphenyl-ethene-1,1-diol 在 dichloroacetic acid buffer 作用下， 以 水 、 乙腈 为溶剂， 生成 Bis-pentamethylphenyl-acetic acid
  参考文献：
  名称：

  羧酸和酯的受阻位烯醇。2,2-双（2,4,6-三甲基苯基）乙烯-1,1-二醇与2,2-双（五甲基苯基）乙烯-1,1-二醇的酮化反应

  摘要：

  已经将两种羧酸的烯醇化酮化，即2,2-双（2,4,6-三甲基苯基）乙烯-1,1-二醇2a和2,2-双（五甲基苯基）乙烯-1,1-二醇2b。在25°C的1∶1乙腈水中进行了研究。这些化合物的稳定性来自β-碳位点质子化的抑制作用，这种作用现已被量化。据报道，对于（Mes）2 C C（OH）2 2a的第一个羟基的电离，p K a为8.18 ，对于（PMP）2 C C（OH）2 2b的p K a为8.63 。已经确定了两种物种在整个pH范围内的pH速率曲线。检测到一般的酸催化作用，产生布朗斯台德（Brønsted）α2a和2b的值分别为0.35和0.34。类似地，对于两种烯醇式单阴离子的一般酸催化计算得出的布朗斯台德α'值分别为0.48和0.45。对相应甲酯的烯醇的酮化的研究已经允许对羧酸，酯和乙烯酮缩醛的烯醇的反应性进行比较研究。Mes 2 C C（OH）（OCH 3）的反应性与烯醇Mes 2 C

  DOI：

  10.1039/a703653a
• 作为产物：
  描述：

  丁一酮,二(戊甲基苯基)- 在 水 作用下， 以 1,4-二氧六环 为溶剂， 生成 2,2-Bis-pentamethylphenyl-ethene-1,1-diol
  参考文献：
  名称：

  Hydration of bis(pentamethylphenyl)- and bismesityl-ketenes leading to ene-1,1-diols (enols of carboxylic acids)

  摘要：

  The reaction of the sterically hindered diarylketenes (Ar = Me5C6 or 2,4,6-Me3C2H2) with water is pH independent over the range 1-9 and is not subject to strong buffer catalysis. The primary products formed are the corresponding ene-1,1-diols which result from addition across the C=O (rather than the C=C) of the ketene. These `enols of carboxylic acids' are relatively long lived owing to slow protonation of the beta-carbon (because of steric hindrance caused by the o-Me groups) and evidence for their structures in solution is presented. On attempted isolation of the ene-l,l -diols facile oxidation to a stable free radical, as well as ketonisation to the corresponding acids, occurs. Evidence is presented in terms of the large negative entropy of activation (ca. 200 J K-1 mol-1), solvent isotope effects and the absence of significant general-base catalysis, that (despite the sterically hindered nature of these ketenes) the characteristics of their hydration are typical of other ketenes and that this most likely involves an initial concerted reaction with a water oligomer. Updated ab initio calculations are also presented, which are consistent with this view.

  DOI：

  10.1039/p29920000927

文献信息

• The first acid and ester enols: 2,2-bis(pentamethylphenyl)ethene-1,1-diol and 1-t-butoxy-2,2-bis(pentamethylphenyl)ethenol, and their oxidation to stable free radicals
  作者：Patrick O'Neill、Anthony F. Hegarty

  DOI：10.1039/c39870000744

  日期：——

  Desilylation of the ketene acetals (5) and (9) provides the ene-1,1-diols (6) and (10) which undergo relatively slow ketonisation and are oxidized to stable free radicals in basic solution.

  乙烯酮缩醛（5）和（9）的脱甲硅烷基化提供烯-1,1-二醇（6）和（10），其经历相对缓慢的酮化并在碱性溶液中被氧化成稳定的自由基。
• NEILL P. O.; HEGARTY A. F., J. CHEM. SOC. CHEM. COMMUN.,(1987) N 10, 744-745
  作者：NEILL P. O.、 HEGARTY A. F.

  DOI：——

  日期：——
• Hydration of bis(pentamethylphenyl)- and bismesityl-ketenes leading to ene-1,1-diols (enols of carboxylic acids)
  作者：Barbara M. Allen、Anthony F. Hegarty、Pat O'Neill、Minh Tho Nguyen

  DOI：10.1039/p29920000927

  日期：——

  The reaction of the sterically hindered diarylketenes (Ar = Me5C6 or 2,4,6-Me3C2H2) with water is pH independent over the range 1-9 and is not subject to strong buffer catalysis. The primary products formed are the corresponding ene-1,1-diols which result from addition across the C=O (rather than the C=C) of the ketene. These `enols of carboxylic acids' are relatively long lived owing to slow protonation of the beta-carbon (because of steric hindrance caused by the o-Me groups) and evidence for their structures in solution is presented. On attempted isolation of the ene-l,l -diols facile oxidation to a stable free radical, as well as ketonisation to the corresponding acids, occurs. Evidence is presented in terms of the large negative entropy of activation (ca. 200 J K-1 mol-1), solvent isotope effects and the absence of significant general-base catalysis, that (despite the sterically hindered nature of these ketenes) the characteristics of their hydration are typical of other ketenes and that this most likely involves an initial concerted reaction with a water oligomer. Updated ab initio calculations are also presented, which are consistent with this view.
• Sterically hindered enols of carboxylic acids and esters. The ketonisation reactions of 2,2-bis(2,4,6-trimethylphenyl)ethene-1,1-diol and 2,2-bis(pentamethylphenyl)ethene-1,1-diol
  作者：Barbara M. Allen、Anthony F. Hegarty、Pat O'Neill

  DOI：10.1039/a703653a

  日期：——

  ketonisation of two enols of carboxylic acids, 2,2-bis(2,4,6-trimethylphenyl)ethene-1,1-diol 2a and 2,2-bis(pentamethylphenyl)ethene-1,1-diol 2b have been studied at 25 °C in 1∶1 acetonitrile–water. The stability of these compounds arises from the inhibition of the β-carbon site to protonation, and this effect is now quantified. A pKa of 8.18 is reported for ionisation of the first hydroxyl group of

  已经将两种羧酸的烯醇化酮化，即2,2-双（2,4,6-三甲基苯基）乙烯-1,1-二醇2a和2,2-双（五甲基苯基）乙烯-1,1-二醇2b。在25°C的1∶1乙腈水中进行了研究。这些化合物的稳定性来自β-碳位点质子化的抑制作用，这种作用现已被量化。据报道，对于（Mes）2 C C（OH）2 2a的第一个羟基的电离，p K a为8.18 ，对于（PMP）2 C C（OH）2 2b的p K a为8.63 。已经确定了两种物种在整个pH范围内的pH速率曲线。检测到一般的酸催化作用，产生布朗斯台德（Brønsted）α2a和2b的值分别为0.35和0.34。类似地，对于两种烯醇式单阴离子的一般酸催化计算得出的布朗斯台德α'值分别为0.48和0.45。对相应甲酯的烯醇的酮化的研究已经允许对羧酸，酯和乙烯酮缩醛的烯醇的反应性进行比较研究。Mes 2 C C（OH）（OCH 3）的反应性与烯醇Mes 2 C