6(Z)-(bromomethylidene)tetrahydro-2-pyranone | 136358-18-4

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 内酯类
• 英文名称: 6(Z)-(bromomethylidene)tetrahydro-2-pyranone
• 英文别名: (Z)-6-(bromomethylene)tetrahydro-2H-pyran-2-one；(6Z)-6-(bromomethylidene)oxan-2-one
• CAS: 136358-18-4
• 化学式: C₆H₇BrO₂
• 分子量: 191.024
• InChiKey: LCRYFNQWSFRVCH-PLNGDYQASA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.3
• 重原子数：
  9
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  26.3
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  5-己炔酸 在 N-溴代丁二酰亚胺(NBS) 、 [{Au(1,3-bis(2,6-diisopropylphenyl)-1H-imidazol-2-ylidene)}₂(μ-OH)][BF₄] 、 silver nitrate 作用下， 以 丙酮 为溶剂， 反应 3.0h， 生成 6(Z)-(bromomethylidene)tetrahydro-2-pyranone
  参考文献：
  名称：

  金（I）催化的炔酸环化：高效，环保地合成γ-，δ-和-内酯

  摘要：

  据报道，使用双核N-杂环卡宾（NHC）-金（I）催化剂可改善γ-，δ-和γ-内酯的合成。这种无溶剂的方法可以以较高的区域和立体选择性获得γ和δ内酯。反应在低催化剂负载下进行，不需要任何添加剂。使用digold预催化剂为功能化的β-内酯提供了一条新的合成途径，而使用以前的方法很难获得。

  DOI：

  10.1002/adsc.201600575

文献信息

• Cyclization of alkynoic acids with gold catalysts: a surprising dichotomy between AuI and AuIII
  作者：Hassina Harkat、Albert Yénimégué Dembelé、Jean-Marc Weibel、Aurélien Blanc、Patrick Pale

  DOI：10.1016/j.tet.2008.10.112

  日期：2009.2

  ω-Acetylenic acids, substituted or not at their acetylenic end, could be efficiently cyclized to γ- or δ-alkylidene lactones in the presence of AuCl and K2CO3. In contrast AuCl3 led to lactone dimers, probably through cyclization and reductive dimerization. These AuI and AuIII catalyzed cyclizations were totally regioselective and most often highly stereoselective.

  在AuCl和K 2 CO 3的存在下，可以在其乙炔基末端取代或不取代的ω-乙炔酸有效地环化为γ-或δ-亚烷基内酯。相反，AuCl 3可能通过环化和还原性二聚而导致内酯二聚体。这些Au I和Au III催化的环化反应完全是区域选择性的，并且通常是高度立体选择性的。
• A mild access to γ- or δ-alkylidene lactones through gold catalysis
  作者：Hassina Harkat、Jean-Marc Weibel、Patrick Pale

  DOI：10.1016/j.tetlet.2006.06.129

  日期：2006.8

  omega-Acetylenic acids are efficiently and stereo selectively converted to the corresponding enol lactones in the presence of catalytic amounts of AuCl and K2CO3. (c) 2006 Elsevier Ltd. All rights reserved.
• Stereoselective Z- and E-bromoenol lactonization of alkynoic acids
  作者：Wei Dai、John A. Katzenellenbogen

  DOI：10.1021/jo00024a035

  日期：1991.11

  We have found that treatment of the silver salt of a 4- or 5-terminal alkynoic acid with bromine results in clean formation of the corresponding Z-bromo enol lactone, the result of a formal cis addition of carboxylate and bromine across the triple bond. This Z-bromo enol lactonization is highly stereoselective and gives good yields in systems that bear substituents on the internal methylene groups; yields with unsubstituted or terminally substituted alkynoic acids are modest. The E-bromo enol lactonization reaction, reported by us previously (Krafft, G. A.; Katzenellenbogen, J. A. J. Am. Chem. Soc. 1981, 103, 5459), has a broader scope and, with modifications, can be performed with high reliability. Mercury(II) salts equilibrate the Z- and E-bromo enol lactones, presumedly by a mercuric ion addition-elimination mechanism. These three reactions provide access to an array of stereoisomeric bromo enol lactone systems.
• US5208244A
  申请人：——

  公开号：US5208244A

  公开（公告）日：1993-05-04