(1R,2S,4aR,4bS,8aS,10aR)-1,4a-Dimethyl-6-oxo-2-trimethylsilanyloxy-dodecahydro-phenanthrene-8a-carboxylic acid methyl ester | 141396-99-8

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 类固醇和类固醇衍生物
• 英文名称: (1R,2S,4aR,4bS,8aS,10aR)-1,4a-Dimethyl-6-oxo-2-trimethylsilanyloxy-dodecahydro-phenanthrene-8a-carboxylic acid methyl ester
• CAS: 141396-99-8
• 化学式: C₂₁H₃₆O₄Si
• 分子量: 380.6
• InChiKey: PQUFZBVJDCLUBN-STMKVKBISA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.58
• 重原子数：
  26.0
• 可旋转键数：
  3.0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.9
• 拓扑面积：
  52.6
• 氢给体数：
  0.0
• 氢受体数：
  4.0

反应信息

• 作为反应物：
  描述：

  (1R,2S,4aR,4bS,8aS,10aR)-1,4a-Dimethyl-6-oxo-2-trimethylsilanyloxy-dodecahydro-phenanthrene-8a-carboxylic acid methyl ester 在 potassium fluoride 作用下， 以 甲醇 为溶剂， 反应 1.0h， 以100%的产率得到(1R,2S,4aR,4bS,8aS,10aR)-2-Hydroxy-1,4a-dimethyl-6-oxo-dodecahydro-phenanthrene-8a-carboxylic acid methyl ester
  参考文献：
  名称：

  Remote oxidation of perhydrophenanthrenes by template-directed hydrogen atom abstraction.

  摘要：

  The use of Breslow's remote functionalization paradigm for installation of an axial C-7 hydroxy group into a perhydrophenanthrene nucleus, with a view toward synthesis of bruceantin (1), has been investigated. The substrates that were evaluated were 9a-c, 11, 17, 18, and 20. Substrates 9a-c all undergo preferential functionalization at C-12. After oxidative cleavage of the initial photoproduct, ketones 18a-c were obtained in yields of 18-26% (36-41%, based on unrecovered starting material). Unsaturated substrate 11 undergoes remote functionalization exclusively at the secondary allylic position (C-12); enone 20 is obtained in 83% overall yield after oxidative cleavage of the initial photoadduct, 19a,b. Thus, in this system, C-12 appears to be the preferred site of intramolecular functionalization. Attempts to block reaction at this position by the use of saturated ketone 18, the derived ketal 17, or enone 20, were all unsuccessful. In the case of 18 the only photoproduct was the intramolecular pinacol. Enone 20 gave an exceedingly complex mixture, consisting of many products. Ketal 17 afforded the unusual macrocyclic lactone 21 in 33% yield. The main conclusion of this study is that it is difficult to extrapolate from the excellent regioselectivity observed by Breslow in the steroid system to the trans-anti-trans perhydrophenanthrene system, which is only slightly less rigid. A second factor which we believe is important in the system we have studied is the apparently minor perturbation of having an equatorial substituent at C-4. We postulate that this substituent, which was not present in the model steroidal systems investigated previously by Breslow, disfavors functionalization at C-7.

  DOI：

  10.1021/jo00040a050
• 作为产物：
  描述：

  (1R,2S,4aR,8aS,10aR)-1,4a-Dimethyl-6-oxo-2-trimethylsilanyloxy-1,3,4,4a,6,7,8,9,10,10a-decahydro-2H-phenanthrene-8a-carboxylic acid methyl ester 在 LiSnCu 作用下， 以 四氢呋喃 、 氨 为溶剂， 反应 1.5h， 以40%的产率得到(1R,2S,4aR,4bS,8aS,10aR)-1,4a-Dimethyl-6-oxo-2-trimethylsilanyloxy-dodecahydro-phenanthrene-8a-carboxylic acid methyl ester
  参考文献：
  名称：

  Remote oxidation of perhydrophenanthrenes by template-directed hydrogen atom abstraction.

  摘要：

  The use of Breslow's remote functionalization paradigm for installation of an axial C-7 hydroxy group into a perhydrophenanthrene nucleus, with a view toward synthesis of bruceantin (1), has been investigated. The substrates that were evaluated were 9a-c, 11, 17, 18, and 20. Substrates 9a-c all undergo preferential functionalization at C-12. After oxidative cleavage of the initial photoproduct, ketones 18a-c were obtained in yields of 18-26% (36-41%, based on unrecovered starting material). Unsaturated substrate 11 undergoes remote functionalization exclusively at the secondary allylic position (C-12); enone 20 is obtained in 83% overall yield after oxidative cleavage of the initial photoadduct, 19a,b. Thus, in this system, C-12 appears to be the preferred site of intramolecular functionalization. Attempts to block reaction at this position by the use of saturated ketone 18, the derived ketal 17, or enone 20, were all unsuccessful. In the case of 18 the only photoproduct was the intramolecular pinacol. Enone 20 gave an exceedingly complex mixture, consisting of many products. Ketal 17 afforded the unusual macrocyclic lactone 21 in 33% yield. The main conclusion of this study is that it is difficult to extrapolate from the excellent regioselectivity observed by Breslow in the steroid system to the trans-anti-trans perhydrophenanthrene system, which is only slightly less rigid. A second factor which we believe is important in the system we have studied is the apparently minor perturbation of having an equatorial substituent at C-4. We postulate that this substituent, which was not present in the model steroidal systems investigated previously by Breslow, disfavors functionalization at C-7.

  DOI：

  10.1021/jo00040a050