(2s*,4R*,6S*)-4,6-dimethyl-2-phenyl-1,3-dioxane | 4233-09-4

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二恶烷
• 英文名称: (2s*,4R*,6S*)-4,6-dimethyl-2-phenyl-1,3-dioxane
• 英文别名: 4,6-dimethyl-2-phenyl-1,3-dioxane
• CAS: 4233-09-4
• 化学式: C₁₂H₁₆O₂
• 分子量: 192.258
• InChiKey: FRKWMMLFFMXPDS-PEGIJTEDSA-N

物化性质

• 沸点：
  275.1±25.0 °C(Predicted)
• 密度：
  0.997±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.9
• 重原子数：
  14.0
• 可旋转键数：
  1.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  18.46
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为反应物：
  描述：

  (2s*,4R*,6S*)-4,6-dimethyl-2-phenyl-1,3-dioxane 在 palladium on activated charcoal 4 A molecular sieve 、 硫酸 、 氢气 、 对甲苯磺酸 作用下， 以 甲醇 、 乙醚 为溶剂， 25.0 ℃ 、101.33 kPa 条件下， 反应 19.0h， 生成 rel-(2S,4R,6S)-2-(1',1'-dimethylethyl)-4,6-dimethyl-1,3-dioxane
  参考文献：
  名称：

  Studies on the mechanism and origin of stereoselective opening of chiral dioxane acetals

  摘要：

  A systematic examination of the mechanism and origin of stereoselection in the reaction of dioxane acetals with allyltrimethylsilane was undertaken. Experimental tests for two limiting mechanisms, synchronous (S(N)2-like) and dissociative (S(N)1-like) substitution processes, were investigated. The meso 2,4,6-trisubstituted 1,3-dioxane acetals cis- and trans-1 provided an interesting opportunity to test the timing of bond breaking and making in the substitution reaction. The modest and C(2)-substituent-dependent selectivity excluded the possibility of a direct S(N)2-type attack on a complexed acetal. Further, the enol ethers 3 and 5 and acyclic acetal 7 were studied as precursors of the putative oxocarbenium ion intermediate in the dissociative limit. The weak and inverted selectivity observed with these substrates ruled out the intermediacy of the extended, separated ion in reactions of the cyclic acetals under similar conditions. A unified mechanistic scheme involving three distinct ion pairs is proposed to explain the dependence of allylation selectivity on structural and experimental variables. The three species are analogous to those proposed in the classic Winstein scheme: (1) an intimate ion pair, (2) an external ion pair, and (3) a separated ion. Each of these proposed intermediates has a different stereochemical profile and the ultimate outcome is a composite of those factors that balance the contribution of the different intermediates. The influence of C(2) substituent, acetal configuration, Lewis acid type and stoichiometry, allylsilane stoichiometry, concentration, solvent, and temperature were investigated and integrated in the proposed mechanistic scheme.

  DOI：

  10.1021/ja00021a040
• 作为产物：
  描述：

  2-trimethylsilyl-2-phenyl-4,6-dimethyl-1,3-dioxane 在 四丁基氟化铵 作用下， 以 四氢呋喃 为溶剂， 反应 3.0h， 生成 (4R^*,6S^*)-4,6-Dimethyl-2-phenyl-1,3-dioxane 、 (2s*,4R*,6S*)-4,6-dimethyl-2-phenyl-1,3-dioxane
  参考文献：
  名称：

  氟化物诱导的 S,S-、O,O- 和 O,S-甲硅烷基化缩醛的原-和碳-脱甲硅烷基化：深入了解化学和立体化学反应结果

  摘要：

  报告了广泛的立体定义的 2-甲硅烷基-1,3-二噻烷、-1,3-二恶烷、-1,3-二氧杂环戊烷和 -1,3-氧杂硫杂环戊烷的化学和立体化学行为的一般概述，当受到氟离子诱导的原-和碳-脱甲硅烷基化。构型的保留或差向异构化似乎不仅取决于芳环上取代基的种类，还取决于甲硅烷基缩醛中杂原子的性质，导致设想出现游离碳负离子或高价甲硅烷基化物质。图形概要

  DOI：

  10.1080/17415993.2013.795225

文献信息

• Intramolecular OH⋅⋅⋅Fluorine Hydrogen Bonding in Saturated, Acyclic Fluorohydrins: The γ-Fluoropropanol Motif
  作者：Bruno Linclau、Florent Peron、Elena Bogdan、Neil Wells、Zhong Wang、Guillaume Compain、Clement Q. Fontenelle、Nicolas Galland、Jean-Yves Le Questel、Jérôme Graton

  DOI：10.1002/chem.201503253

  日期：2015.12.1

  is commonly exercised in compound property optimization. However, the influence of fluorination on hydrogen‐bond (HB) properties of adjacent functional groups, as well as the HB‐accepting capacity of fluorine itself, is still not completely understood. Although the formation of OH⋅⋅⋅F intramolecular HBs (IMHBs) has been established for conformationally restricted fluorohydrins, such interaction in

  氟化通常用于化合物性能优化。然而，氟化对相邻官能团氢键（HB）性质以及氟本身的HB接受能力的影响尚不完全清楚。尽管构象限制的氟代醇可以形成 OH⋅⋅⋅F 分子内 HBs (IMHBs)，但柔性化合物中的这种相互作用仍然存在疑问。与之前的报道相比，本文首次证明了无环饱和 γ-氟代醇中存在 OH⋅⋅⋅F IMHB，甚至对于母体 3-氟丙-1-醇也是如此。相对立体化学对相应的h1 J OH⋅⋅⋅F值具有至关重要的影响，如syn ‐ 和anti- 4-氟戊烷-2-ol (6.6 和 1.9 Hz) 所示。OH⋅⋅⋅F IMHBs 的大小及其对整体分子构象、氟化基序和烷基取代水平的强烈依赖性，通过量子化学计算得到了合理化。对于给定的烷基链，“屏蔽规则”适用于 OH⋅⋅⋅F IMHB 能量。令人惊讶的是，预测的 OH⋅⋅⋅F IMHB 能量仅比相应的 OH⋅⋅⋅OMe 弱一些。这些结果为脂肪醇氟化的影
• Conformer Equilibria in 2,4-Disubstituted Pentane Derivatives
  作者：Reinhard W. Hoffmann、Dirk Stenkamp、Thomas Trieselmann、Richard Göttlich

  DOI：10.1002/(sici)1099-0690(199911)1999:11<2915::aid-ejoc2915>3.0.co;2-r

  日期：1999.11

  only two conformations. Substituents have been varied in order to find those which lead to a strong preference of the conformer equilibrium. Studying 2-substituted 4-methylpentanes 3 and 4-benzyloxypentanes 12, it has been shown that substituent effects on the conformer equilibria are not additive, as would be expected on the grounds of steric effects alone. Rather, interactions between polar groups

  2,4-二取代戊烷是基本上仅采用两种构象的分子。为了找到导致构象异构体平衡的强烈偏好的取代基，已经改变了取代基。研究 2-取代的 4-甲基戊烷 3 和 4-苄氧基戊烷 12，已经表明取代基对构象异构体平衡的影响不是相加的，正如仅基于空间效应所预期的那样。相反，极性基团之间的相互作用加强了构象异构体平衡的偏差。当应用于 2,4-二取代戊烷时，氯或邻苯二甲酰亚胺等取代基将构象异构体平衡移动到 gg 构象异构体一侧，优先级超过 90%。
• Studies on the mechanism and origin of stereoselective opening of chiral dioxane acetals
  作者：Scott E. Denmark、Neil G. Almstead

  DOI：10.1021/ja00021a040

  日期：1991.10

  A systematic examination of the mechanism and origin of stereoselection in the reaction of dioxane acetals with allyltrimethylsilane was undertaken. Experimental tests for two limiting mechanisms, synchronous (S(N)2-like) and dissociative (S(N)1-like) substitution processes, were investigated. The meso 2,4,6-trisubstituted 1,3-dioxane acetals cis- and trans-1 provided an interesting opportunity to test the timing of bond breaking and making in the substitution reaction. The modest and C(2)-substituent-dependent selectivity excluded the possibility of a direct S(N)2-type attack on a complexed acetal. Further, the enol ethers 3 and 5 and acyclic acetal 7 were studied as precursors of the putative oxocarbenium ion intermediate in the dissociative limit. The weak and inverted selectivity observed with these substrates ruled out the intermediacy of the extended, separated ion in reactions of the cyclic acetals under similar conditions. A unified mechanistic scheme involving three distinct ion pairs is proposed to explain the dependence of allylation selectivity on structural and experimental variables. The three species are analogous to those proposed in the classic Winstein scheme: (1) an intimate ion pair, (2) an external ion pair, and (3) a separated ion. Each of these proposed intermediates has a different stereochemical profile and the ultimate outcome is a composite of those factors that balance the contribution of the different intermediates. The influence of C(2) substituent, acetal configuration, Lewis acid type and stoichiometry, allylsilane stoichiometry, concentration, solvent, and temperature were investigated and integrated in the proposed mechanistic scheme.
• Fluoride-induced proto- and carbo-desilylation of S,S-, O,O- and O,S-silylated acetals: an insight into the chemical and stereochemical reaction outcome
  作者：Antonella Capperucci、Mariafrancesca Fochi、Andrea Mazzanti、Salvatore Pollicino

  DOI：10.1080/17415993.2013.795225

  日期：2013.12.1

  A general overview on the chemical and stereochemical behavior of a wide range of stereodefined 2-silyl-1,3-dithianes, -1,3-dioxanes, -1,3-dioxolanes and -1,3-oxathiolanes is reported, when subjected to fluoride ion-induced proto- and carbo-desilylation. Retention of configuration or epimerization appears to depend not only on the kind of the substituents on the aromatic ring, but also on the nature

  报告了广泛的立体定义的 2-甲硅烷基-1,3-二噻烷、-1,3-二恶烷、-1,3-二氧杂环戊烷和 -1,3-氧杂硫杂环戊烷的化学和立体化学行为的一般概述，当受到氟离子诱导的原-和碳-脱甲硅烷基化。构型的保留或差向异构化似乎不仅取决于芳环上取代基的种类，还取决于甲硅烷基缩醛中杂原子的性质，导致设想出现游离碳负离子或高价甲硅烷基化物质。图形概要