(R)-1-<1-hydroxy-2-(pivaloyloxy)ethyl>-2-<<(tert-butyldimethylsilyl)oxy>methyl>benzene | 173074-03-8

• 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: (R)-1-<1-hydroxy-2-(pivaloyloxy)ethyl>-2-<<(tert-butyldimethylsilyl)oxy>methyl>benzene
• CAS: 173074-03-8
• 化学式: C₂₀H₃₄O₄Si
• 分子量: 366.573
• InChiKey: SZDKYKLCWQJHRQ-KRWDZBQOSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.83
• 重原子数：
  25.0
• 可旋转键数：
  6.0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.65
• 拓扑面积：
  55.76
• 氢给体数：
  1.0
• 氢受体数：
  4.0

反应信息

• 作为反应物：
  描述：

  (R)-1-<1-hydroxy-2-(pivaloyloxy)ethyl>-2-<<(tert-butyldimethylsilyl)oxy>methyl>benzene 在 lithium aluminium tetrahydride 、 草酰氯 、 4-甲基苯磺酸吡啶 、 二甲基亚砜 、 三乙胺 作用下， 以 乙醚 、 二氯甲烷 为溶剂， 反应 4.83h， 生成 (S)-[2-(tert-Butyl-dimethyl-silanyloxymethyl)-phenyl]-(1-methoxy-1-methyl-ethoxy)-acetaldehyde
  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：

  三甲基乙酰氯 、 1-[2-(tert-Butyl-dimethyl-silanyloxymethyl)-phenyl]-ethane-1,2-diol 在 4-二甲氨基吡啶 作用下， 以 吡啶 为溶剂， 反应 1.0h， 以81%的产率得到(R)-1-<1-hydroxy-2-(pivaloyloxy)ethyl>-2-<<(tert-butyldimethylsilyl)oxy>methyl>benzene
  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