2-methyl-4-<2,4-dimethoxy-6-<<(tert-butyldimethylsilyl)oxy>methyl>phenyl>-3-butyn-2-ol | 173074-00-5

• 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: 2-methyl-4-<2,4-dimethoxy-6-<<(tert-butyldimethylsilyl)oxy>methyl>phenyl>-3-butyn-2-ol
• 英文别名: 4-[2-[[Tert-butyl(dimethyl)silyl]oxymethyl]-4,6-dimethoxyphenyl]-2-methylbut-3-yn-2-ol
• CAS: 173074-00-5
• 化学式: C₂₀H₃₂O₄Si
• 分子量: 364.557
• InChiKey: FIMAXQDHBDRWOD-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.35
• 重原子数：
  25
• 可旋转键数：
  8
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  47.9
• 氢给体数：
  1
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  2-methyl-4-<2,4-dimethoxy-6-<<(tert-butyldimethylsilyl)oxy>methyl>phenyl>-3-butyn-2-ol 在 sodium hydroxide 作用下， 以 苯 为溶剂， 反应 30.0h， 以91%的产率得到2,4-dimethoxy-6-<<(tert-butyldimethylsilyl)oxy>methyl>ethynylbenzene
  参考文献：
  名称：

  Taxane Synthesis through Intramolecular Pinacol Coupling at C-1−C-2. Highly Oxygenated C-Aromatic Taxanes

  摘要：

  Chiral, nonracemic intramolecular pinacol coupling substrates 3/20 and 30 have been prepared from ethyl isopropyl ketone and acryloyl chloride, which provide the A-ring and either o-iodobenzyl alcohol or 2,4-dimethoxybenzyl alcohol, which provide the respective aromatic C-rings, in 14-16 linear steps in overall yields of approximately 20%. Potential pinacol coupling substrate 23 could not be made available for investigation due to intervening pinacol rearrangement in the acetonide formation step. 3/20 undergo stereoselective cyclizations mediated by TiCl4-Zn in which the C-9 oxygen substituent plays the dominant role in determining the stereochemical outcome at C-l and C-2 in the respective tricyclic products 4 and 21. The formation of 21 is the more stereoselective process. The reagent of choice for the transformation of 30 into 31 is SmI2, which, although less stereoselective than TiCl4-Zn, leads to higher yielding carbon-carbon bond formation relative to carbonyl reduction. These pinacol cyclizations are interpreted to occur through endo boat-chair transition structures that prefer to orient the developing C-2 substituent and the preexisting C-9 substituent equatorially. Pinacol product 31 was converted through three additional steps into 40 having a B-ring closely related to that of taxol. We believe that these studies indicate pinacol cyclizations at C-1-C-2 to have considerable potential for producing advanced intermediates for syntheses of taxol and related complex taxanes.

  DOI：

  10.1021/jo9519367
• 作为产物：
  描述：

  3,5-二甲氧基苄醇 在 咪唑 、 copper(l) iodide 、 双氧水 、 碘 、 溶剂黄146 、 二乙胺 、 三苯基膦 、 palladium dichloride 作用下， 以 二氯甲烷 为溶剂， 反应 55.0h， 生成 2-methyl-4-<2,4-dimethoxy-6-<<(tert-butyldimethylsilyl)oxy>methyl>phenyl>-3-butyn-2-ol
  参考文献：
  名称：

  Taxane Synthesis through Intramolecular Pinacol Coupling at C-1−C-2. Highly Oxygenated C-Aromatic Taxanes

  摘要：

  Chiral, nonracemic intramolecular pinacol coupling substrates 3/20 and 30 have been prepared from ethyl isopropyl ketone and acryloyl chloride, which provide the A-ring and either o-iodobenzyl alcohol or 2,4-dimethoxybenzyl alcohol, which provide the respective aromatic C-rings, in 14-16 linear steps in overall yields of approximately 20%. Potential pinacol coupling substrate 23 could not be made available for investigation due to intervening pinacol rearrangement in the acetonide formation step. 3/20 undergo stereoselective cyclizations mediated by TiCl4-Zn in which the C-9 oxygen substituent plays the dominant role in determining the stereochemical outcome at C-l and C-2 in the respective tricyclic products 4 and 21. The formation of 21 is the more stereoselective process. The reagent of choice for the transformation of 30 into 31 is SmI2, which, although less stereoselective than TiCl4-Zn, leads to higher yielding carbon-carbon bond formation relative to carbonyl reduction. These pinacol cyclizations are interpreted to occur through endo boat-chair transition structures that prefer to orient the developing C-2 substituent and the preexisting C-9 substituent equatorially. Pinacol product 31 was converted through three additional steps into 40 having a B-ring closely related to that of taxol. We believe that these studies indicate pinacol cyclizations at C-1-C-2 to have considerable potential for producing advanced intermediates for syntheses of taxol and related complex taxanes.

  DOI：

  10.1021/jo9519367

文献信息

• Taxane Synthesis through Intramolecular Pinacol Coupling at C-1−C-2. Highly Oxygenated C-Aromatic Taxanes
  作者：Charles S. Swindell、Weiming Fan

  DOI：10.1021/jo9519367

  日期：1996.1.1

  Chiral, nonracemic intramolecular pinacol coupling substrates 3/20 and 30 have been prepared from ethyl isopropyl ketone and acryloyl chloride, which provide the A-ring and either o-iodobenzyl alcohol or 2,4-dimethoxybenzyl alcohol, which provide the respective aromatic C-rings, in 14-16 linear steps in overall yields of approximately 20%. Potential pinacol coupling substrate 23 could not be made available for investigation due to intervening pinacol rearrangement in the acetonide formation step. 3/20 undergo stereoselective cyclizations mediated by TiCl4-Zn in which the C-9 oxygen substituent plays the dominant role in determining the stereochemical outcome at C-l and C-2 in the respective tricyclic products 4 and 21. The formation of 21 is the more stereoselective process. The reagent of choice for the transformation of 30 into 31 is SmI2, which, although less stereoselective than TiCl4-Zn, leads to higher yielding carbon-carbon bond formation relative to carbonyl reduction. These pinacol cyclizations are interpreted to occur through endo boat-chair transition structures that prefer to orient the developing C-2 substituent and the preexisting C-9 substituent equatorially. Pinacol product 31 was converted through three additional steps into 40 having a B-ring closely related to that of taxol. We believe that these studies indicate pinacol cyclizations at C-1-C-2 to have considerable potential for producing advanced intermediates for syntheses of taxol and related complex taxanes.