2-[(4R,5R)-2,2-dimethyl-5-(2,6,6-trimethyl-5-oxocyclohexen-1-yl)-1,3-dioxolan-4-yl]benzaldehyde | 159143-35-8

• 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: 2-[(4R,5R)-2,2-dimethyl-5-(2,6,6-trimethyl-5-oxocyclohexen-1-yl)-1,3-dioxolan-4-yl]benzaldehyde
• CAS: 159143-35-8
• 化学式: C₂₁H₂₆O₄
• 分子量: 342.435
• InChiKey: VJWIXTGDKYTESV-RTBURBONSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.2
• 重原子数：
  25
• 可旋转键数：
  3
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.52
• 拓扑面积：
  52.6
• 氢给体数：
  0
• 氢受体数：
  4

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]benzaldehyde 在 吡啶 、 四氯化钛 、 锌 作用下， 以 四氢呋喃 为溶剂， 反应 38.5h， 生成
  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：

  2-碘苄醇 在 Lindlar catalyst 吡啶 、 咪唑 、 喹啉 、 manganese(IV) oxide 、 sodium hydroxide 、 copper(l) iodide 、 lithium aluminium tetrahydride 、 草酰氯 、 potassium dioxotetrahydroxoosmate(VI) 、 四丁基氟化铵 、 氢气 、 4-甲基苯磺酸吡啶 、 potassium carbonate 、 氢化奎尼定 1,4-(2,3-二氮杂萘)二醚 、 二乙胺 、 三乙胺 、 三苯基膦 、 calcium carbonate 、 mercury dichloride 、 palladium dichloride 、 potassium hexacyanoferrate(III) 作用下， 以 四氢呋喃 、 水 、 乙腈 、 叔丁醇 为溶剂， 生成 2-[(4R,5R)-2,2-dimethyl-5-(2,6,6-trimethyl-5-oxocyclohexen-1-yl)-1,3-dioxolan-4-yl]benzaldehyde
  参考文献：
  名称：

  Pinacol closure of oxygenated taxane skeleta at C-1-C-2 with stereoinduction by oxygen substituents at C-9 and C-10

  摘要：

  The treatment of keto aldehydes 4 and 5 with low-valent Ti results in stereoselective intramolecular pinacol couplings that lead to optically active oxygenated taxane skeleta 2 and 3.

  DOI：

  10.1016/s0040-4039(00)73292-8