(2S,3S)-6-methoxy-2-(3,4-dimethoxyphenyl)-3-methyl-2,3-dihydro-5-benzofuran | 134453-23-9

• 分子结构分类: 有机化合物 - 苯丙烷和聚酮 - 2-芳基苯并呋喃类黄酮
• 英文名称: (2S,3S)-6-methoxy-2-(3,4-dimethoxyphenyl)-3-methyl-2,3-dihydro-5-benzofuran
• 英文别名: (2S,3S)-2-(3,4-dimethoxyphenyl)-6-methoxy-3-methyl-2,3-dihydro-1-benzofuran-5-ol
• CAS: 134453-23-9
• 化学式: C₁₈H₂₀O₅
• 分子量: 316.354
• InChiKey: YELZOBATXOVYIK-YPMLDQLKSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.3
• 重原子数：
  23
• 可旋转键数：
  4
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.33
• 拓扑面积：
  57.2
• 氢给体数：
  1
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  (2S,3S)-6-methoxy-2-(3,4-dimethoxyphenyl)-3-methyl-2,3-dihydro-5-benzofuran 在 potassium carbonate 、 N,N-二甲基苯胺 作用下， 以 丙酮 为溶剂， 反应 52.0h， 生成 (2S,3S)-4-allyl-2-(3,4-dimethoxyphenyl)-6-methoxy-3-methyl-2,3-dihydro-5-benzofuranol
  参考文献：
  名称：

  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

  摘要：

  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.

  DOI：

  10.1021/jo982164s
• 作为产物：
  描述：

  (1S,6R,7R,8R)-8-(3,4-dimethoxyphenyl)-3-methoxy-7-methylbicyclo[4.2.0]oct-3-ene-2,5-dione 在 titanium(IV) isopropylate 、 (+)-C₃₆H₃₂O₄ 、 四氯化钛 作用下， 以 二氯甲烷 为溶剂， 以94%的产率得到(2S,3S)-6-methoxy-2-(3,4-dimethoxyphenyl)-3-methyl-2,3-dihydro-5-benzofuran
  参考文献：
  名称：

  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

  摘要：

  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.

  DOI：

  10.1021/jo982164s

文献信息

• Stereoselective 3 + 2 and stereospecific 2 + 2 cycloaddition reactions of alkenes and quinones
  作者：Thomas A. Engler、Keith D. Combrink、James E. Ray

  DOI：10.1021/ja00231a084

  日期：1988.11

  mM NaCl and 25 mM tris-acetate at pH 7.0.14 After 0.5 h incubation at 24 OC, 4 mM dithiothreitol was added to initiate strand cleavage. The reaction was allowed to continue for 6 h (24 "C). The double strand cleavage products were separated on a 0.4% vertical agarose gel which resolves DNA segments up to 25 kbp in size (Figure 3). Therefore, DNA uniquely labeled at the R and

  pH 7.0.14 的 mM NaCl 和 25 mM tris-乙酸盐 在 24 ℃下孵育 0.5 小时后，加入 4 mM 二硫苏糖醇以启动链裂解。使反应持续 6 小时（24°C）。双链切割产物在 0.4% 垂直琼脂糖凝胶上分离，该凝胶可解析大小高达 25 kbp 的 DNA 片段（图 3）。因此，DNA 在R 和
• Stereospecific Lewis Acid-Promoted Reactions of Styrenyl Systems with 2-Alkoxy-(6-Alkyl)-1,4-Benzoquinones: Scope, Limitations, and Synthetic Applications
  作者：Thomas A. Engler、Keith D. Combrink、Michael A. Letavic、Kenneth O. Lynch、James E. Ray

  DOI：10.1021/jo00101a016

  日期：1994.11

  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.
• Lewis Acid-Directed Reactions of Quinones with Styrenyl Systems:  The Case of 2-Methoxy-3-methyl-1,4-benzoquinone
  作者：Thomas A. Engler、Rajesh Iyengar

  DOI：10.1021/jo971937u

  日期：1998.3.1

  Reactions of 2-methoxy-3-methyl-1,4-benzoquinone with various (E)-1-propenylbenzenes promoted by 1 equiv of Ti(IV), as a 1:1 mixture of TiCl4-Ti(O-i-Pr)(4), produce rel-(1S, 6R, 7R, 8R)-8-aryl-4,7-dimethyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5-diones 3 and trans-2-aryl-3,7-dimethyl-6-methoxy-2,3-dihydro-5-benzofuranols 5 as the major products. Reactions promoted by 2 equiv of Ti(IV) as a 1:1 mixture of TiC1l(4)-Ti(O-i-Pr)(4) or 1 equiv of either TiCl4, SnCl4, or BF3 . OEt2 give regioisomeric rel-(1R, 6S, 7R, 8R)-7-aryl-4,8-dimethyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5-diones (4) and/or trans-2-aryl-3,6-dimethyl-7-methoxy-2,3-dihydro-5-benzofuranols (6). A mechanism involving regioselective coordination of the various Lewis acids to the quinone is used to explain the formation of the products. These reactions demonstrate the effective regiocontrol exerted over the reactions by the nature of the Lewis acid promoters. Cyclobutanes 3 and 4 cleanly undergo rearrangement to the corresponding benzofuranols 5 and 6 on treatment with protic acid. In contrast, reactions of 2-methoxy-1,4-benzoquinone promoted by either BF3 . OEt2 or Ti(IV), as 1 equiv or excess amounts of TiCl4 or 1:1 TiCl4-Ti(O-i-Pr)(4), all afford the same regioisomeric products, i.e., rel-(1S, 6R, 7R, 8R)-8-aryl-7-methyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5-dione 25 and/or trans-2-aryl-3-methyl-6-methoxy-2,3-dihydro-5-benzofuranol 27.
• 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：——
• 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.