7a-methylperhydrobenzofuran | 106553-40-6

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 苯并呋喃
• 英文名称: 7a-methylperhydrobenzofuran
• 英文别名: cis-octahydro-7a-methylbenzofuran；cis-7a-methyloctahydrobenzofuran；7a-methylperhydrobenzo[b]furan；(3aS,7aS)-7a-methyl-3,3a,4,5,6,7-hexahydro-2H-1-benzofuran
• CAS: 106553-40-6
• 化学式: C₉H₁₆O
• 分子量: 140.225
• InChiKey: QJDDIMJWOGYCGI-IUCAKERBSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.1
• 重原子数：
  10
• 可旋转键数：
  0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  9.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为产物：
  描述：

  2-烯丙基环己酮 在 三乙基硅烷 、 四氧化锇 、 N-甲基吗啉氧化物 、 三氟乙酸 作用下， 以 四氢呋喃 、 二氯甲烷 、 水 、 乙腈 为溶剂， 反应 7.67h， 生成 7a-methylperhydrobenzofuran
  参考文献：
  名称：

  固醇生物合成的C环问题：TiCl（4）诱导重排成对应于C环的抗马尔可夫尼科夫阳离子。

  摘要：

  [反应：参见文本]阳离子9，由二醇8和BF（3）.Et（2）O，SnCl（4），Sc（OTf）（3），FeCl（3），TiF（4）反应生成或CF（3）SO（3）H导致氢化物转移，提供阳离子11，这对应于主链重排的开始。另一方面，TiCl（4）通过扩环选择性地诱导重排至仲阳离子13，这对应于固醇生物合成的C环形成。AlCl（3）和ZrCl（4）诱导进一步重排为六元环叔阳离子16。

  DOI：

  10.1021/ol0057582

文献信息

• The C-Ring Problem of Sterol Biosynthesis:  TiCl₄-Induced Rearrangement into the Anti-Markovnikov Cation Corresponding to the C-Ring
  作者：Mugio Nishizawa、Yoshihiro Iwamoto、Hiroko Takao、Hiroshi Imagawa、Takumichi Sugihara

  DOI：10.1021/ol0057582

  日期：2000.6.1

  [reaction: see text] Cation 9, generated by the reaction of diol 8 and BF(3).Et(2)O, SnCl(4), Sc(OTf)(3), FeCl(3), TiF(4), or CF(3)SO(3)H, leads to a hydride shift, providing cation 11, which corresponds to the initiation of backbone rearrangement. On the other hand, TiCl(4) selectively induces rearrangement to secondary cation 13 by ring expansion, which corresponds to the C-ring formation of sterol

  [反应：参见文本]阳离子9，由二醇8和BF（3）.Et（2）O，SnCl（4），Sc（OTf）（3），FeCl（3），TiF（4）反应生成或CF（3）SO（3）H导致氢化物转移，提供阳离子11，这对应于主链重排的开始。另一方面，TiCl（4）通过扩环选择性地诱导重排至仲阳离子13，这对应于固醇生物合成的C环形成。AlCl（3）和ZrCl（4）诱导进一步重排为六元环叔阳离子16。
• Carr, Graham; Whittaker, David, Journal of the Chemical Society. Perkin transactions II, 1989, p. 359 - 366
  作者：Carr, Graham、Whittaker, David

  DOI：——

  日期：——
• Reversibility Effects on the Stereoselectivity of Pt(II)-Mediated Cascade Poly-ene Cyclizations
  作者：Jeremiah A. Feducia、Michel R. Gagné

  DOI：10.1021/ja075518i

  日期：2008.1.1

  Cyclization of 1,5-dienes bearing nucleophilic traps with electrophilic trisphosphine pincer ligated Pt(II) complexes results in the formation of a polycyclic Pt-alkyl via a pt(n(2)-alkene) intermediate. With electron-rich triphosphine ligands, an equilibrium between the pt(n(2)-alkene) and Pt-alkyl was observed. The position of the equilibrium was sensitive to ligand basicity, conjugate acid strength, solvent polarity, and ring size. In cases where the ligand was electron poor and did not promote retrocyclization, the kinetic products adhering to the Stork-Eschenmoser postulate were observed (E-alkenes give trans-ring junctions). When retrocyclization was rapid, alternative thermodynamic products resulting from multistep rearrangements were observed (cis-[6,5]-bicycles). Under both kinetic and thermodynamic conditions, remote methyl substituents led to highly diastereoselective reactions. In the case of trienol substrates, long-range asymmetric induction from a C-ring substituent was considerably attenuated and only modest diastereoselectivity was observed (similar to 2:1). The data suggest that for a tricyclization, the long-range stereocontrol results from diastereo-selecting interactions that develop during the organization of the nascent rings. In contrast, the bicyclization diastereoselectivities result from reversible cascade cyclization.
• Experimental and theoretical approaches into the C- and D-ring problems of sterol biosynthesis. Hydride shift versus C–C bond migration due to cation conformational changes controlled by the counteranion
  作者：Mugio Nishizawa、Arpita Yadav、Yoshihiro Iwamoto、Hiroshi Imagawa

  DOI：10.1016/j.tet.2004.07.064

  日期：2004.10

  spirocyclic ether 21 was formed as the sole product via a tert-cationic intermediate 16 through 1,2-hydride shift. However, the treatment with TiCl4 afforded six-membered ring products 22, 23, 24, 25, 26, and 27 via the ring expansion into the unstable six-membered ring secondary cation 17. Occurrence of both α and β chloride 23 and 24 is distinctive evidence of the existence of secondary cation 17, ruling

  从实验和理论的角度，通过使用模型化合物，研究了固醇生物合成的C环和D环问题，即一种酶如何克服马尔可夫尼科夫壁的问题。当用BF 3 ·Et 2 O，SnCl 4，TiF 4，Sc（OTf）3，FeCl 3或TfOH处理模型二醇20时，螺环醚21经由叔阳离子中间体16至1形成为唯一产物。，2-氢化物转移。然而，用TiCl 4处理4，得到六元环的产品22，23，24，25，26，和27通过环膨胀进入不稳定六元环二次阳离子17。α和β氯化物23和24的出现是存在次级阳离子17的独特证据，排除了协同机制的想法。裸阳离子15的分子力学计算阐明了两个可能的构象异构体，平行的15 - I（五元环和阳离子平面），有利于氢化物移位生成16和垂直的15 - II，从而导致C-C键迁移至17。在抗衡阴离子（例如[TiCl 4 OH] -，[TiF 4 OH] -，[BF 3 OH] -和[OTf] -）存在下对阳