(+/-)-cis-hexahydro-6a-methyl-2-oxo-6aH-cyclopentafuran | 24871-13-4

• 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: (+/-)-cis-hexahydro-6a-methyl-2-oxo-6aH-cyclopentafuran
• 英文别名: 1-Methyl-2-oxabicyclo<3.3.0^1,5>octan-3-one；cis-hexahydro-6a-methyl-2H-cycloheptafuran-2-one；cis-hexahydro-6a-methyl-2H-cyclopenta[b]furan-2-one；6a-methylhexahydrocyclopenta[b]furan-2-one；(3aS,6aS)-6a-methyl-3a,4,5,6-tetrahydro-3H-cyclopenta[b]furan-2-one
• CAS: 24871-13-4
• 化学式: C₈H₁₂O₂
• 分子量: 140.182
• InChiKey: YMRRWQZJYFEWQT-XPUUQOCRSA-N

物化性质

• 沸点：
  240.3±8.0 °C(Predicted)
• 密度：
  1.119±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  1.2
• 重原子数：
  10
• 可旋转键数：
  0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.88
• 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-氯-2-戊酮 在 盐酸 、 六甲基磷酰三胺 、 正丁基锂 、 magnesium 、 乙二胺 作用下， 以 四氢呋喃 、 甲醇 为溶剂， 反应 14.83h， 生成 (+/-)-cis-hexahydro-6a-methyl-2-oxo-6aH-cyclopentafuran
  参考文献：
  名称：

  Reductive Cyclization of Ketones Tethered to Activated Olefins Mediated by Magnesium in Methanol

  摘要：

  The reductive cyclizations of various ketones tethered to activated olefins such as alpha,beta-unsaturated esters, nitriles, sulfoxides, and sulfides were mediated by magnesium in dry methanol in the presence of mercuric chloride. When treated with magnesium in dry methanol at -23-degrees-C all of the ketones except nitrile 9 (42%) and 5-oxa-8-keto-2-enoate 5 (13%) gave excellent yields (79-98%) of mono- and bicyclic alcohol products resulting from carbon-carbon bond formation between the beta-carbon of the activated olefin and the carbonyl carbon. The reaction was accelerated by the catalytic amount of mercuric chloride, although the stereoselectivity was not affected by the catalyst. For all the substrates except 8-keto-2-enoate 3 and 5-aza-8-keto-2-enoate 6, the configuration of the major product was trans between the hydroxy and (methoxycarbonyl)methyl groups. The product isomer ratios were independent of the substrate geometry (E or Z). In contrast to the ketones, aldehydes tethered to alpha,beta-unsaturated esters gave products of simple reduction of the double bond and/or saturated alcohols instead of the cyclized products. When the reaction temperature was lowered, the yields of cyclized product were significantly affected by the production of appreciable amounts of saturated product, but the stereoselectivity was not improved. Under the same reaction conditions alpha,beta-unsaturated sulfoxide 16 gave deoxygenated sulfide 18 (85%) as the major product along with a small amount (9%) of cyclized product 19t. In contrast, sulfone 17 underwent desulfonylation instead of cyclization to give olefin 20 (54%). With excess magnesium (15 equiv), however, alpha,beta-unsaturated sulfoxide 16 gave cyclized sulfide 19t (95%) via deoxygenated sulfide 18. Both 16Z and 16E afforded product 19t as a single isomer. It is suggested that the reductive cyclization of the alpha,beta-unsaturated esters and nitriles proceed by means of nucleophilic attack of a beta-carbon radical anion, formed by initial electron transfer from magnesium metal to the activated olefin, on the carbonyl group. The cyclization of the alpha,beta-unsaturated sulfide proceeds by nucleophilic attack of the ketyl on the olefinic double bond.

  DOI：

  10.1021/jo00085a036

文献信息

• Samarium(II) Iodide-Mediated Intramolecular Conjugate Additions of α,β-Unsaturated Lactones
  作者：Gary A. Molander、David J. St. Jean

  DOI：10.1021/jo0255936

  日期：2002.5.1

  promote intramolecular conjugate additions of alkyl halides onto alpha,beta-unsaturated lactones. This process has been shown to be applicable to a number of alpha,beta-unsaturated lactones, including tetrasubstituted olefins, and has been demonstrated to be quite general for the formation of saturated bicyclic and tricyclic lactones. The method presented herein provides a mild, efficient process to form

  在催化量的碘化镍（II）的存在下，碘化II（II）已用于促进烷基卤化物分子内共轭加成到α，β-不饱和内酯上。已经表明该方法适用于许多α，β-不饱和内酯，包括四取代的烯烃，并且已经证明对于形成饱和的双环和三环内酯是相当普遍的。本文提出的方法提供了一种温和，有效的方法，以从简单的前体形成结构复杂的内酯。
• Improved enantioselection for chiral dirhodium(II) carboxamide-catalysed carbon-hydrogen insertion reactions of tertiary alkyl diazoacetates
  作者：Michael P. Doyle、Qi-Lin Zhou、Conrad E. Raab、Gregory H.P. Roos

  DOI：10.1016/0040-4039(95)00927-5

  日期：1995.7

  Enantiocontrol in CH insertion reactions of 3° alkyl diazoacetates, which is highly dependent on the catalyst ligand, is greatly enhanced with the use of dirhodium(II) tetrakis[methyl 1-acetylimidazolidin-2-one-4(S)-carboxylate], Rh2(4S-MACIM)4.

  高度依赖于催化剂配体的3°重氮烷基乙酸CH插入反应中的对映体控制通过使用四[甲基1-乙酰基咪唑烷二甲基-2-酮-4（S）-羧酸盐]（II）来大大增强]，Rh 2（4S-MACIM）4。
• The development of a new catalytic process: Bu3SnH-catalyzed reductive cyclization of enals and enones
  作者：David S Hays、Gregory C Fu

  DOI：10.1016/s0040-4020(99)00446-9

  日期：1999.7

  By sequencing two known reactions, a new catalytic carbon-carbon bond-forming process, the Bu3SnH-catalyzed, PhSiH3-mediated reductive cyclization of enals and enones, has been developed. The addition of EtOH to the reactions leads to reproducibly good yields of the cyclized products; a rationale for including this additive is provided.

  通过对两个已知的反应进行测序，已开发出一种新的催化碳-碳键形成过程，即Bu 3 SnH催化的PhSiH 3介导的烯和烯酮的还原环化反应。将EtOH添加到反应中可导致环化产物的可重复生产的良好收率；提供了包括这种添加剂的理由。
• Lewis acid promoted decomposition of unsaturated .alpha.-diazo ketones. 1. An efficient approach to simple and annulated cyclopentenones
  作者：Amos B. Smith、Bruce H. Toder、Stephen J. Branca、R. Karl Dieter

  DOI：10.1021/ja00398a021

  日期：1981.4
• Diastereoselective Synthesis of γ-Butyrolactones from Enones Mediated or Catalyzed by a Titanocene Complex
  作者：Natasha M. Kablaoui、Frederick A. Hicks、Stephen L. Buchwald

  DOI：10.1021/ja960953q

  日期：1996.1.1