(1R*,5R*,6R*,7R*)-3-hydroxy-6-methyl-7-phenylbicyclo<3.2.1>oct-3-ene-2,8-dione | 126402-10-6

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (1R*,5R*,6R*,7R*)-3-hydroxy-6-methyl-7-phenylbicyclo<3.2.1>oct-3-ene-2,8-dione
• 英文别名: (1R,5R,6R,7R)-3-hydroxy-6-methyl-7-phenylbicyclo[3.2.1]oct-3-ene-2,8-dione
• CAS: 126402-10-6；134453-30-8；134453-31-9
• 化学式: C₁₅H₁₄O₃
• 分子量: 242.274
• InChiKey: DVPJMMIMWMZLBX-SKZLGDCLSA-N

物化性质

• 沸点：
  461.5±45.0 °C(Predicted)
• 密度：
  1.285±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.4
• 重原子数：
  18
• 可旋转键数：
  1
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.33
• 拓扑面积：
  54.4
• 氢给体数：
  1
• 氢受体数：
  3

反应信息

• 作为产物：
  描述：

  1-丙烯基苯 、 2-[(4-methoxyphenyl)methoxy]cyclohexa-2,5-diene-1,4-dione 在 titanium(IV) isopropylate 、 四氯化钛 作用下， 以 二氯甲烷 为溶剂， 以59%的产率得到(1R*,5R*,6R*,7R*)-3-hydroxy-6-methyl-7-phenylbicyclo<3.2.1>oct-3-ene-2,8-dione
  参考文献：
  名称：

  Stereospecific Lewis Acid-Promoted Reactions of Styrenyl Systems with 2-Alkoxy-(6-Alkyl)-1,4-Benzoquinones: Scope, Limitations, and Synthetic Applications

  摘要：

  Titanium(IV)-promoted reactions of various (E)-1-propenylbenzenes with 2-methoxy- and 2-methoxy-6-methyl-1,4-benzoquinones produce trans 2-aryl-6-methoxy-3-(and 4-di)methyl-2,3-dihydro-5-benzofuranols (10-12), rel-(1S,6R,7R,8R)-3-methoxy-8-aryl-7-(and 1-di)methylbicyclo[4.2.0]oct-3-ene-2,5-diones (2 + 2 cycloadducts, 13-15) and/or rel-(1R,5R,6R,7R)-7-aryl-3-hydroxy-6-(and 4)methylbicyclo[3.2.1]oct-3-ene-2,8-diones (5 + 2 cycloadducts, 16/17). In many cases, each of the three products can be obtained selectively in good yield by control of reaction conditions and/or by choice of substituents on the quinone or the propenylbenzene. The dihydrobenzofurans are formed stereoselectively, whereas the formation of the bicyclo[4.2.0] systems are stereospecific processes. Thus, reactions of (Z)-1-propenylbenzenes afford rel-(1R,6S,7R,8R)-8-aryl-3-methoxy-7-methylbicyclo[4.2.0]oct-3-ene-2,5-diones (24, 25). No bicyclo[3.2.1]systems. are found in reactions of the (Z)-propenylbenzenes. The products all apparently result from a thermally allowed 2 pi + 4 pi (2 + 5) cycloaddition of the propenylbenzene with a 2-methoxy-4-oxo-2,5-cyclohexadienyl carbocation intermediate (26) formed by coordination of the Ti(IV) to the C-1 carbonyl oxygen of the quinone. In the cycloaddition, the aryl ring of the propenylbenzene occupies an endo position with respect to the pentadienyl carbocation moiety of 26 and the bicyclo[3.2.1] carbocation product of the cycloaddition (28/29) either undergoes dealkylation or rearrangment to yield the observed products. Treatment of the bicylo[4.2.0] systems with protic acid effects their rearrangement to the dihydrobenzofuranols. Reactions of 2-propenylbenzenes and arylcycloalkenes with the quinones regioselectively give dihydrobenzofuranols 43-45 and 49-54, respectively; a 2 + 2 cycloadduct is found in low yield in only one case. The 7-aryl-3-hydroxy-6-methylbicyclo[3.2.1]oct-3-ene-2,8-diones are produced exclusively in reactions of 2-((4-methoxybenzyl)oxy)-1,4-benzoquinones with various propenylbenzenes. Application of these reactions to the synthesis of (+/-)-obtusafuran, (+/-)-liliflol-B, (+/-)-kadsurenone, and (+/-) denudatin are reported.

  DOI：

  10.1021/jo00101a016

文献信息

• Isolation of bicyclo[3.2.1]oct-3-ene-2,8-dione products (formal 5 + 2 cycloadducts) from reactions of styrenes with 2-alkoxy-1,4-benzoquinones
  作者：Thomas A. Engler、Keith D. Combrink、Fusao Takusagawa

  DOI：10.1039/c39890001573

  日期：——

  Titanium(IV) catalysed reactions of 2-alkoxy-1,4-benzoquinones and various trans-β-methylstyrenes stereoselectivity produce 7-aryl-3-hydroxy-6-methylbicyclo[3.2.1]oct-3-ene-2,8-diones in moderate yield.

  钛（IV）催化2-烷氧基-1,4-苯醌和各种反式-β-甲基苯乙烯的立体选择性，生成7-芳基-3-羟基-6-甲基双环[3.2.1] oct-3-ene-2,8 -二酮产量中等。
• Lewis Acid-Controlled Regioselectivity in Reactions of Styrenyl Systems with Benzoquinone Monoimides:  New Regioselective Syntheses of Substituted 2-Aryl-2,3-dihydrobenzofurans, 2-Aryl-2,3-dihydroindoles, and 2-Arylindoles
  作者：Thomas A. Engler、Wenying Chai、Kenneth O. LaTessa

  DOI：10.1021/jo9617068

  日期：1996.1.1

  Reactions of 4-(N-phenylsulfonyl)-2-alkoxy-1,4-benzoquinone monoimines 2-4 with electron-rich propenylbenzenes promoted by BF3 yield 7-alkoxy-2-aryl-3-methyl-5-[(N-phenylsulfonyl)amino]2,3-dihydrobenzofurans 5-7 nearly exclusively, whereas promotion of the reactions by Ti4+ gives mixtures of the dihydrobenzofurans and their N-(phenylsulfonyl)-6-alkoxy-2-aryl-5-hydroxy-3-methyl-2,3-dihydroindole isomers 8-10, depending upon substituents present on the propenylbenzene. However, reactions promoted with excess Ti4+, as mixtures of TiCl4:Ti(OiPr)(4), give the dihydroindoles as nearly the exclusive products. Evidence for a mechanism involving initial 5 + 2 cycloaddition of the Lewis acid-bound quinone monoimide with the propenylbenzene is found in reactions of styrenes 1f/g with monoimide 3 in which 7-aryl-3-hydroxy-6-methylbicyclo[3.2.1]oct-3-ene-2,8-diones 33 (5 + 2 adducts) are isolated. These reactions have been applied to stereoselective syntheses of pterocarpans bearing N-phenylsulfonyl groups, azapterocarpans and diazapterocarpans. In addition, DDQ oxidation of derivatives of several of the 2-aryl-2,3-dihydroindoles afford the corresponding 2-arylindoles in good yield. Finally, the experimental details of a general synthetic approach to 7-alkoxy-benzofuranoid neolignans, including (+/-)-licarin B and eupomatenoids-1 and -12 are reported.
• Engler, Thomas A.; Letavic, Michael A.; Reddy, Jayachandra P., Journal of the American Chemical Society, 1991, vol. 113, # 13, p. 5068 - 5070
  作者：Engler, Thomas A.、Letavic, Michael A.、Reddy, Jayachandra P.

  DOI：——

  日期：——
• Selective control of the various cycloaddition products from reactions of styrenes and 1,4-benzoquinones: optimization of the formal 5 + 2 cycloadducts
  作者：Thomas A. Engler、Michael A. Letavic、Keith D. Combrink、Fusao Takusagawa

  DOI：10.1021/jo00310a005

  日期：1990.11
• Asymmetric Reactions of 2-Methoxy-1,4-benzoquinones with Styrenyl Systems:  Enantioselective Syntheses of 8-Aryl-3-methoxybicyclo[4.2.0]oct-3-en-2,5-diones, 7-Aryl-3-hydroxybicyclo[3.2.1]oct-3-en-2,8-diones, 2-Aryl-6-methoxy-2,3-dihydrobenzofuran-5-ols, and Pterocarpans
  作者：Thomas A. Engler、Michael A. Letavic、Rajesh Iyengar、Kenneth O. LaTessa、Jayachandra P. Reddy

  DOI：10.1021/jo982164s

  日期：1999.4.1

  Reactions of 2-methoxy-1,4-benzoquinones 2 and 3 with (E)-propenylbenzenes 1 promoted at -78 degrees C by Ti(IV)-TADDOLates prepared from diol-(+)- 4 afford (1R,6R,7R,8R)-8-aryl-3-methoxy-7methylbicyclo[4.2.0]oct-3-en-2,5-diones 5/8 or (1R,5R,6R,7R)-7-aryl-3-hydroxy-6-methylbicyclo-3-en-2,8-diones 7/10 in good yield and high ee. (2S,3S)-2-Aryl-6-methoxy-3-methyl-2,3-dihydrobenzofuran-5-ols 6/9 are also found, but in slightly lower ee. Cyclobutanes 5/8 cleanly and efficiently rearrange to the dihydrobenzofurans 6/9 without loss of enantiomeric purity upon treatment with the Ti-TADDOLates at higher temperatures. Reactions of (Z)-propenylbenzene 17 and of indene with 2 and 3 give products in moderate enantiomeric purity. Products obtained from reactions of 1-anisylcycloalkenes with 2 differ significantly in yield and enantiomeric purity. In the latter reactions, the ee's of the cyclobutane products are consistently much higher than those of the dihydrobenzofuran products. More significantly, products of different absolute configuration result from different cycloalkenes. With 1-anisylcyclopentene or 1-anisylcyclohexene, all of the products are of similar configuration and are obtained in comparable yields and ee's. However, 1-anisylcycloheptene affords products that are diastereomeric with those of the 1-anisylcyclopentene, and in lower ee's. A mechanistic model is proposed. Application of these reactions to the enantioselective synthesis of the pterocarpan class of isoflavonoid natural products is also reported.