meso-2,3-Diethyl-1,4-diphenyl-1,4-butanedione

• 分子结构分类: 有机化合物 - 木脂素、新木脂素和相关化合物 - 二苄基丁烷木脂素
• 英文名称: meso-2,3-Diethyl-1,4-diphenyl-1,4-butanedione
• 英文别名: meso-2,3-diethyl-1,4-diphenyl-1,4-butandione；(2R*,3S*)-2,3-diethyl-1,4-diphenylbutane-1,4-dione；meso-3,4-dibenzoylhexane；(2R,3S)-2,3-diethyl-1,4-diphenylbutane-1,4-dione
• 化学式: C₂₀H₂₂O₂
• 分子量: 294.393
• InChiKey: VPTYWKURXRCQFU-HDICACEKSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.7
• 重原子数：
  22
• 可旋转键数：
  7
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.3
• 拓扑面积：
  34.1
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  meso-2,3-Diethyl-1,4-diphenyl-1,4-butanedione 在 盐酸 作用下， 以 甲醇 、 氯仿 为溶剂， 生成 3,4-Diethyl-2,5-diphenylfuran
  参考文献：
  名称：

  Intermediates in the Paal-Knorr Synthesis of Furans

  摘要：

  New experimental evidence for the mechanism of the Paal-Knorr reaction involving the acid-catalyzed cyclization of a 1,4-diketone to form a furan is reported. In aqueous or alcoholic solutions containing hydrochloric acid and in chloroform containing boron trifluoride-etherate d,l- and meso-3,4-diethyl-2,5-hexanediones (2r and 2m) cyclize at unequal rates; the stereochemical configuration of the unchanged done is preserved during the reaction. This disagrees with the commonly accepted mechanism involving the ring closure of the rapidly formed monoenol (11b) followed by loss of water. A pathway involving the rapid protonation of one of the carbonyls followed by the electrophilic attack on the protonated carbonyl by the enol being formed at the other carbonyl group (10c) is proposed to account for the difference in reaction rates between the diastereomers of 3,4-disubstituted 2,5-hexanediones (1-3). The following results also seem to support the intermediacy of 10c. The presence of two isopropyl groups in 3,4-diisopropyl-2,5-hexanedione (3) considerably reduces the rate of cyclization, The catalytic constants k(H)(+) for the cyclization of 2r and 2m are larger than the constants for enolization of methyl ketones. The diastereomers of 2,3-dimethyl-and 2,3-diethyl-1,4-diphenyl-1,4-butanediones (4 and 5), which could enolize only toward the center of the molecule, also react at different rates. The d,l and meso dideuterio analogs (d(2)-4r and d(2)-4m) exhibit a primary isotope effect during cyclization. The order of cyclization of 1,4-diphenyl-1,4-butanedione (6) and its analogs (7-9) reveals that the presence of electron-donating groups facilitate the reaction.

  DOI：

  10.1021/jo00107a006
• 作为产物：
  描述：

  苯丁酮 在 lead dioxide 作用下， 以 苯 为溶剂， 反应 20.0h， 以40 mg的产率得到meso-2,3-Diethyl-1,4-diphenyl-1,4-butanedione
  参考文献：
  名称：

  分子间光氧化还原偶联：替代 Norrish II 型反应和带 γ-C-H 键的酮中的阳环化

  摘要：

  报道了丁酰苯光转化的新反应途径。除了 Norrish II 型断裂和 Yang 环化之外，还会产生分子间物质：1,2-二苯甲酰乙烷、2-苯甲酰乙腈和频哪醇。他们约占。20% 的转化原料，类似于杨产品。苯乙酮烯醇中间体已被确定为拟议机械步骤的 H 原子供体。

  DOI：

  10.1002/ejoc.202100434

文献信息

• Bioinspired total synthesis of tetrahydrofuran lignans by tandem nucleophilic addition/redox isomerization/oxidative coupling and cycloetherification reactions as key steps
  作者：Pratap R. Jagtap、Ivana Císařová、Ullrich Jahn

  DOI：10.1039/c7ob02848b

  日期：——

  A very short three-step approach to trans,trans,trans-2,5-diaryl-3,4-dimethyltetrahydrofuran lignans is reported. The carbon skeleton is assembled in a single step based on an unprecedented tandem reaction consisting of 1,2-addition of aryllithium reagents to α,β-unsaturated aldehydes, ruthenium-catalyzed redox isomerization of the resulting alkoxides to enolates and their dimerization triggered by

  据报道，反式，反式，反式-2,5-二芳基-3,4-二甲基四氢呋喃木脂素的非常短的三步法。碳骨架是基于空前的串联反应由一个步骤组装而成的，该串联反应由芳基锂试剂与α，β-不饱和醛的1,2-加成反应，钌催化的所得醇盐氧化还原异构化为烯醇化物以及它们的二聚反应引发。电子氧化。形成的2，3-二烷基-1，4-二酮具有中等至良好的d / l-非对映选择性，并通过还原和非对映选择性环醚化转化为目标四氢呋喃木脂素。
• Intermediates in the Paal-Knorr Synthesis of Furans
  作者：Venkataraman Amarnath、Kalyani Amarnath

  DOI：10.1021/jo00107a006

  日期：1995.1

  New experimental evidence for the mechanism of the Paal-Knorr reaction involving the acid-catalyzed cyclization of a 1,4-diketone to form a furan is reported. In aqueous or alcoholic solutions containing hydrochloric acid and in chloroform containing boron trifluoride-etherate d,l- and meso-3,4-diethyl-2,5-hexanediones (2r and 2m) cyclize at unequal rates; the stereochemical configuration of the unchanged done is preserved during the reaction. This disagrees with the commonly accepted mechanism involving the ring closure of the rapidly formed monoenol (11b) followed by loss of water. A pathway involving the rapid protonation of one of the carbonyls followed by the electrophilic attack on the protonated carbonyl by the enol being formed at the other carbonyl group (10c) is proposed to account for the difference in reaction rates between the diastereomers of 3,4-disubstituted 2,5-hexanediones (1-3). The following results also seem to support the intermediacy of 10c. The presence of two isopropyl groups in 3,4-diisopropyl-2,5-hexanedione (3) considerably reduces the rate of cyclization, The catalytic constants k(H)(+) for the cyclization of 2r and 2m are larger than the constants for enolization of methyl ketones. The diastereomers of 2,3-dimethyl-and 2,3-diethyl-1,4-diphenyl-1,4-butanediones (4 and 5), which could enolize only toward the center of the molecule, also react at different rates. The d,l and meso dideuterio analogs (d(2)-4r and d(2)-4m) exhibit a primary isotope effect during cyclization. The order of cyclization of 1,4-diphenyl-1,4-butanedione (6) and its analogs (7-9) reveals that the presence of electron-donating groups facilitate the reaction.
• Intermolecular Photoredox Coupling: Alternative to Norrish Type II Reaction and Yang Cyclization in Ketones with γ‐C−H Bonds
  作者：Heiko Hoffmann、Michael W. Tausch

  DOI：10.1002/ejoc.202100434

  日期：2021.7.15

  A new reaction pathway of the photoconversion of butyrophenone is reported. In addition to the Norrish type II fragmentation and Yang cyclization, intermolecular species are generated: 1,2-Dibenzoylethane, 2-phenacylacetonitrile and pinacols. They account for approx. 20 % of the converted starting material, similar to the Yang product. The acetophenone enol intermediate has been identified as an H-atom

  报道了丁酰苯光转化的新反应途径。除了 Norrish II 型断裂和 Yang 环化之外，还会产生分子间物质：1,2-二苯甲酰乙烷、2-苯甲酰乙腈和频哪醇。他们约占。20% 的转化原料，类似于杨产品。苯乙酮烯醇中间体已被确定为拟议机械步骤的 H 原子供体。