2-[(4R,5R)-2,2-dimethyl-5-(2,6,6-trimethyl-5-oxocyclohexen-1-yl)-1,3-dioxolan-4-yl]-3,5-dimethoxybenzaldehyde | 173073-87-5

• 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-[(4R,5R)-2,2-dimethyl-5-(2,6,6-trimethyl-5-oxocyclohexen-1-yl)-1,3-dioxolan-4-yl]-3,5-dimethoxybenzaldehyde
• CAS: 173073-87-5
• 化学式: C₂₃H₃₀O₆
• 分子量: 402.488
• InChiKey: HUKPPYQPCBRTMC-NHCUHLMSSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.1
• 重原子数：
  29
• 可旋转键数：
  5
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.57
• 拓扑面积：
  71.1
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  2-[(4R,5R)-2,2-dimethyl-5-(2,6,6-trimethyl-5-oxocyclohexen-1-yl)-1,3-dioxolan-4-yl]-3,5-dimethoxybenzaldehyde 在 吡啶 、 4-二甲氨基吡啶 、 samarium diiodide 、 水 、 4-甲基苯磺酸吡啶 作用下， 以 四氢呋喃 、 二氯甲烷 为溶剂， 反应 20.5h， 生成 [(1S,2S,9R,10R)-1,9,10-trihydroxy-5,7-dimethoxy-12,15,15-trimethyl-2-tricyclo[9.3.1.03,8]pentadeca-3(8),4,6,11-tetraenyl] acetate
  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：

  5,5-(ethylenedioxy)-2,,6,6-trimethyl-1-iodocyclohexene 在 manganese(IV) oxide 、 三氟化硼乙醚 、 四丁基氟化铵 、 叔丁基锂 、 4-甲基苯磺酸吡啶 、 calcium carbonate 、 mercury dichloride 作用下， 以 四氢呋喃 、 二氯甲烷 、 水 、 乙腈 、 苯 为溶剂， 反应 40.0h， 生成 2-[(4R,5R)-2,2-dimethyl-5-(2,6,6-trimethyl-5-oxocyclohexen-1-yl)-1,3-dioxolan-4-yl]-3,5-dimethoxybenzaldehyde
  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.