3,4-Dimethoxybenzyl pivalate | 157843-80-6

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: 3,4-Dimethoxybenzyl pivalate
• 英文别名: (3,4-Dimethoxyphenyl)methyl 2,2-dimethylpropanoate
• CAS: 157843-80-6
• 化学式: C₁₄H₂₀O₄
• 分子量: 252.31
• InChiKey: VREMGDTVNLBHKZ-UHFFFAOYSA-N

物化性质

• 沸点：
  321.1±27.0 °C(Predicted)
• 密度：
  1.052±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.6
• 重原子数：
  18
• 可旋转键数：
  6
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  44.8
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  3,4-Dimethoxybenzyl pivalate 以7%的产率得到
  参考文献：
  名称：

  Pincock J.A., Wedge P.J., J. Org. Chem., 59 (1994) N 19, 5587-5595

  摘要：

  DOI：
• 作为产物：
  描述：

  3,4-二甲氧基苯甲醛 在 吡啶 、 sodium tetrahydroborate 作用下， 以 甲醇 、 苯 为溶剂， 生成 3,4-Dimethoxybenzyl pivalate
  参考文献：
  名称：

  The Photochemistry of Methoxy-Substituted Benzyl Acetates and Benzyl Pivalates: Homolytic vs Heterolytic Cleavage

  摘要：

  The multiple methoxy-substituted benzyl acetates (3g-i) and benzyl pivalates (4g-i) have been photolyzed in methanol solution. The products of these reactions are derived from two critical intermediates; the benzyl radical/acyloxy radical pair and the benzyl cation/carboxylate anion pair. As predicted by the meta effect, the yield of ion-derived product, the methyl ether in this case, was enhanced by the presence of the m-methoxy groups. The yield of ether, for the acetate esters, varied from 2% for the 4-methoxy-substituted ester to 66% for the 3,4,5-trimethoxy-substituted ester. In contrast, the yield of ether, for the pivalate esters, varied from <1% for the 4-methoxy-substituted ester to 20% for the 3,4,5-trimethoxy-substituted one. The meta effect does not explain these differences; electron transfer converting the radical pair to the ion pair is still an important pathway in the mechanism for ion formation. A quantitative analysis of the yield of the ethers was done in order to obtain the electron-transfer rate constants. This analysis revealed that the yield of the ethers was higher than expected based on previous results for other substituted benzyl acetates. A possible explanation for this discrepancy is that internal return of the radical pair to starting material for the acetate esters is more efficient than for the pivalate esters. Also, the esters 3k and 3l, were prepared to study the effect of electron-withdrawing groups in the meta position. For these esters, the benzylic cleavage reactions were inefficient and an isomerization reaction, the benzvalene rearrangement, was competitive.

  DOI：

  10.1021/jo00098a016

文献信息

• Direct Synthesis of Thioethers from Carboxylates and Thiols Catalyzed by FeCl₃
  作者：Kunuru Venkatesham、Chitturi Bhujanga Rao、Chanti Babu Dokuburra、Richard A. Bunce、Yenamandra Venkateswarlu

  DOI：10.1021/acs.joc.5b02143

  日期：2015.11.20

  A new and efficient method has been developed for the synthesis of thioethers from carboxylates and thiols. The reaction proceeds via a Fe(III)-catalyzed direct displacement of carboxylates from benzylic or allylic esters by heterocyclic thiols. Short reaction times, good to excellent yields of products, and few side reactions are the significant features of the new protocol.

  已经开发了一种新的有效方法，用于从羧酸盐和硫醇合成硫醚。该反应通过杂环硫醇通过Fe（III）催化的羧酸酯从苄基或烯丙基酯直接置换而进行。新协议的显着特点是反应时间短，产品收率好至极好，副反应少。
• Pincock J.A., Wedge P.J., J. Org. Chem., 59 (1994) N 19, 5587-5595
  作者：Pincock J.A., Wedge P.J.

  DOI：——

  日期：——
• The Photochemistry of Methoxy-Substituted Benzyl Acetates and Benzyl Pivalates: Homolytic vs Heterolytic Cleavage
  作者：J. A. Pincock、P. J. Wedge

  DOI：10.1021/jo00098a016

  日期：1994.9

  The multiple methoxy-substituted benzyl acetates (3g-i) and benzyl pivalates (4g-i) have been photolyzed in methanol solution. The products of these reactions are derived from two critical intermediates; the benzyl radical/acyloxy radical pair and the benzyl cation/carboxylate anion pair. As predicted by the meta effect, the yield of ion-derived product, the methyl ether in this case, was enhanced by the presence of the m-methoxy groups. The yield of ether, for the acetate esters, varied from 2% for the 4-methoxy-substituted ester to 66% for the 3,4,5-trimethoxy-substituted ester. In contrast, the yield of ether, for the pivalate esters, varied from <1% for the 4-methoxy-substituted ester to 20% for the 3,4,5-trimethoxy-substituted one. The meta effect does not explain these differences; electron transfer converting the radical pair to the ion pair is still an important pathway in the mechanism for ion formation. A quantitative analysis of the yield of the ethers was done in order to obtain the electron-transfer rate constants. This analysis revealed that the yield of the ethers was higher than expected based on previous results for other substituted benzyl acetates. A possible explanation for this discrepancy is that internal return of the radical pair to starting material for the acetate esters is more efficient than for the pivalate esters. Also, the esters 3k and 3l, were prepared to study the effect of electron-withdrawing groups in the meta position. For these esters, the benzylic cleavage reactions were inefficient and an isomerization reaction, the benzvalene rearrangement, was competitive.