(Z)-3-benzyl-5-benzylidene-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one | 952718-58-0

• 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: (Z)-3-benzyl-5-benzylidene-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one
• 英文别名: (5Z)-3-benzyl-5-benzylidene-4-prop-1-en-2-ylpyran-2-one
• CAS: 952718-58-0
• 化学式: C₂₂H₂₀O₂
• 分子量: 316.4
• InChiKey: OWOSHQVEPFWZOD-CPNJWEJPSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5
• 重原子数：
  24
• 可旋转键数：
  4
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.14
• 拓扑面积：
  26.3
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  (Z)-3-benzyl-5-benzylidene-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one 在 palladium on activated charcoal 氢气 作用下， 以 甲醇 为溶剂， 20.0 ℃ 、101.33 kPa 条件下， 反应 5.0h， 以88%的产率得到3,5-dibenzyl-4-isopropyl-5,6-dihydropyran-2-one
  参考文献：
  名称：

  trans-RhCl(CO)(PPh₃)₂-Catalyzed Monomeric and Dimeric Cycloisomerization of Propargylic 2,3-Dienoates. Establishment of α,β-Unsaturated δ-Lactone Rings by Cyclometallation

  摘要：

  Cyclometallation of two unsaturated carbon-carbon bonds usually requires the application of low-valent metal catalysts, which could cleave the propargylic ester linkage. Thus, it is desirable to identify a catalyst which could undergo cyclometallation without cleaving the propargylic ester linkage. In this paper, we used trans-RhCI(CO)(PPh3)(2) to realize the cyclometallation of propargylic 2,3-dienoates. The substituents at the 4-position of allenoate moiety nicely control the reaction pathway: when the 4-position of propargylic 2,3-dienoate 1 was monosubstituted with an aryl group, the bicyclic intermediate 7 formed by the cyclometallation could highly selectively undergo carbometalation with the alkyne moiety in the second molecule of propargylic 2,3-dienoate 1 to afford metallabicyclic intermediates 8a or 8b. Subsequent reductive elimination would afford 9, which could undergo an intramolecular Diels-Alder reaction resulting in the formation of polycyclic bis(delta-lactone)-containing structures 2. The intermediate could be trapped by adding 3-methoxyprop-1-yne affording cyclization-aromatization product 4p highly selectively. If the substituent at the 4-positon of the 2,3-allenoate moiety has a beta-H atom, sequential unimolecular cyclometallation/beta-H elimination/reductive elimination occurs to afford cross-conjugated 5(Z)-alkylidene-4-alkenyl-5,6-dihydropyran-2-ones. The Z-stereochemistry of the exo double bond was determined by the cyclometallation. Some of the a,p-unsaturated delta-lactones could be easily converted to other synthetically useful compounds via reduction reaction, hydrogenation, and iodination/coupling protocol.

  DOI：

  10.1021/ja073582u
• 作为产物：
  描述：

  3'-phenylprop-2'-ynyl 2-benzyl-4-methylpenta-2,3-dienoate 在 trans-RhCl(CO)(PPh₃)2 作用下， 以 甲苯 为溶剂， 反应 15.0h， 以67%的产率得到(Z)-3-benzyl-5-benzylidene-4-(prop-1-en-2-yl)-5,6-dihydropyran-2-one
  参考文献：
  名称：

  trans-RhCl(CO)(PPh₃)₂-Catalyzed Monomeric and Dimeric Cycloisomerization of Propargylic 2,3-Dienoates. Establishment of α,β-Unsaturated δ-Lactone Rings by Cyclometallation

  摘要：

  Cyclometallation of two unsaturated carbon-carbon bonds usually requires the application of low-valent metal catalysts, which could cleave the propargylic ester linkage. Thus, it is desirable to identify a catalyst which could undergo cyclometallation without cleaving the propargylic ester linkage. In this paper, we used trans-RhCI(CO)(PPh3)(2) to realize the cyclometallation of propargylic 2,3-dienoates. The substituents at the 4-position of allenoate moiety nicely control the reaction pathway: when the 4-position of propargylic 2,3-dienoate 1 was monosubstituted with an aryl group, the bicyclic intermediate 7 formed by the cyclometallation could highly selectively undergo carbometalation with the alkyne moiety in the second molecule of propargylic 2,3-dienoate 1 to afford metallabicyclic intermediates 8a or 8b. Subsequent reductive elimination would afford 9, which could undergo an intramolecular Diels-Alder reaction resulting in the formation of polycyclic bis(delta-lactone)-containing structures 2. The intermediate could be trapped by adding 3-methoxyprop-1-yne affording cyclization-aromatization product 4p highly selectively. If the substituent at the 4-positon of the 2,3-allenoate moiety has a beta-H atom, sequential unimolecular cyclometallation/beta-H elimination/reductive elimination occurs to afford cross-conjugated 5(Z)-alkylidene-4-alkenyl-5,6-dihydropyran-2-ones. The Z-stereochemistry of the exo double bond was determined by the cyclometallation. Some of the a,p-unsaturated delta-lactones could be easily converted to other synthetically useful compounds via reduction reaction, hydrogenation, and iodination/coupling protocol.

  DOI：

  10.1021/ja073582u