9-methyl-9,10-dihydrophenanthren-4-ol | 75703-42-3

• 分子结构分类: 有机化合物 - 苯类化合物 - 菲及其衍生物
• 英文名称: 9-methyl-9,10-dihydrophenanthren-4-ol
• CAS: 75703-42-3
• 化学式: C₁₅H₁₄O
• 分子量: 210.276
• InChiKey: RSDJKYOKGOSDLM-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.72
• 重原子数：
  16.0
• 可旋转键数：
  0.0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.2
• 拓扑面积：
  20.23
• 氢给体数：
  1.0
• 氢受体数：
  1.0

反应信息

• 作为产物：
  描述：

  2-(2'-hydroxyphenyl)-α,α-dimethylbenzyl alcohol 以 水 、 乙腈 为溶剂， 反应 2.0h， 以40%的产率得到9-甲基菲
  参考文献：
  名称：

  Photocyclization of 2-(2'-hydroxyphenyl)benzyl alcohol and derivatives via o-quinonemethide type intermediates

  摘要：

  A new photochemical reaction, the photocyclization of 2-(2'-hydroxyphenyl)benzyl alcohol (1) and derivatives to 6H-dibenzo[b,d]pyrans, is reported. The quantum yield for cyclization of 1 to give pyran 7 is 0.50 +/- 0.04 in aqueous solutions of pH > 10. At lower pH, PHI is significantly lower. For example at pH 7, PHI = 0.25 +/- 0.03. Results from investigations of structure-reactivity, pH effects, and fluorescence data suggest a mechanism in which the primary step involves ionization of the phenol moiety to phenolate in S1, which is probably followed by (or is concerted with) twisting of the phenyl rings to give a more planar species in the excited state. This is subsequently followed by (or is concerted with) a dehydroxylation step of the benzyl alcohol moiety (all on the S1 surface) to give an omicron-quinonemethide type intermediate 20 and deactivation back to the ground-state surface. Electrocyclic ring closure of this intermediate gives the observed pyran. Nucleophilic trapping of this electrophilic intermediate by solvent (e.g., MeOH) to give the methyl ether is also observed when photolysis is carried out in MeOH. The proposed reaction pathway is unprecedented: it takes advantage of the tendency of biphenyl systems to be planar in the excited state as well as the enhanced electron-donating effect of the phenolate anion, which is required for the dehydroxylation step.

  DOI：

  10.1021/ja00020a033