ethyl 2-methyl-3-oxohept-6-ynoate | 134906-09-5

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 酮酸及其衍生物
• 英文名称: ethyl 2-methyl-3-oxohept-6-ynoate
• 英文别名: 6-Heptynoic acid, 2-methyl-3-oxo-, ethyl ester
• CAS: 134906-09-5
• 化学式: C₁₀H₁₄O₃
• 分子量: 182.219
• InChiKey: UOHMRLYFSCYDDL-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.4
• 重原子数：
  13
• 可旋转键数：
  6
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  43.4
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  ethyl 2-methyl-3-oxohept-6-ynoate 在 manganese triacetate 、 lithium chloride 作用下， 以 溶剂黄146 为溶剂， 反应 19.0h， 以77%的产率得到Ethyl 2-Chloro-2-methyl-3-oxo-6-heptynoate
  参考文献：
  名称：

  Solvent effects on manganese(III)-based oxidative free-radical cyclizations: ethanol and acetic acid

  摘要：

  Ethanol complements the typical solvent, acetic acid, for Mn(III)-based oxidative free-radical cyclizations. Cyclization of enol ether 1c to give gibberellic acid intermediate 6c is successful in ethanol, but not in acetic acid. Ethanol acts as a reducing agent for primary radicals, converting 13 and 33 to alkanes 17 and 32. Acetylenes can be used as substrates since the vinyl radicals 24 and 25 are reduced by ethanol to alkenes 26-28. The 1-hydroxyethyl radical obtained from ethanol is oxidized to acetaldehyde by Mn(III). The effect of solvent on the oxidative cyclization of unsaturated beta-keto esters 35 and 48 was examined. A higher percentage of 5-exo product is obtained in ethanol. The primary cyclopentanemethyl radicals 40 and 53 are oxidized mainly to alkenes 43 and 57 in ethanol and mainly to the alcohols 42 and 55 and lactones 41 and 58 in acetic acid.

  DOI：

  10.1021/jo00019a014
• 作为产物：
  描述：

  炔丙基脲 、 3-乙氧基-2-甲基-3-氧代丙酸钾 生成 ethyl 2-methyl-3-oxohept-6-ynoate
  参考文献：
  名称：

  Synthesis of 2,5-Disubstituted Furans via Palladium-Catalyzed Annulation of Alkyl 3-Oxo-6-heptynoates

  摘要：

  The reaction of the readily available alkyl 3-oxo-6-heptynoates with aryl halides in the presence of K2CO3 and catalytic amounts of Pd(PPh3)(4) at 100 degrees C provides a valuable new route to 2,5-disubstituted furans 3. Most probably, the furan ring is generated through an annulation reaction promoted by sigma-arylpalladium complexes generated in situ and involving the nucleophilic attack of the ketonic oxygen across the carbon-carbon triple bond coordinated to palladium, followed by the base-catalyzed isomerization of the resultant stereoisomeric 2,5-dialkylidenetetrahydrofuran intermediates 4 and 5. The reaction is highly chemoselective. No evidence was obtained of carboannulation products. The reaction temperature has proven to be crucial for the success of the methodology. The K2CO3:alkyne ratio also affects the reaction outcome. The highest yields of furan derivatives have been obtained with aryl halides containing electron-withdrawing substituents, very likely because the higher acidity of the methylene protons of 4 and 5 favors the isomerization step. Extension of the methodology to methyl 3-oxo-7-substituted-6-heptynoates leads to the formation of 2,5-disubstituted furans containing a branched side chain. The presence of an alkyl substituent on the C-2 of the staring alkyne, however, seems to prevent the isomerization step. Treatment of ethyl 2-methyl-3-oxo-6-heptynoate under our standard conditions produced in fact the 2,5-dialkylidene derivative 5p in 42% yield, and no evidence of the corresponding furan derivative was attained.

  DOI：

  10.1021/jo962386v

文献信息

• Formal Syntheses of (±)-Platensimycin and (±)-Platencin via a Dual-Mode Lewis Acid Induced Cascade Cyclization Approach
  作者：Lizhi Zhu、Congshan Zhou、Wei Yang、Shuzhong He、Gui-Juan Cheng、Xinhao Zhang、Chi-Sing Lee

  DOI：10.1021/jo401105q

  日期：2013.8.16

  efficient dual-mode Lewis acid induced Diels–Alder (DA)/carbocyclization cascade cyclization reaction has been developed for construction of the tricyclic core of ent-kaurenoids in one pot with the aid of a theoretical study on the π,σ-Lewis acidities of a variety of Lewis acids. With ZnBr2 as the dual-mode Lewis acid, a series of substituted enones and dienes underwent DA/carbocyclization cascade cyclization

  诱导的狄尔斯-阿尔德（DA）的温和和有效的双模路易斯酸/ carbocyclization级联环化反应已被用于建筑的三环核心的开发耳鼻喉科-kaurenoids一锅与理论研究对π的辅助下，σ-各种路易斯酸的路易斯酸度。以ZnBr 2为双模路易斯酸，一系列取代的烯酮和二烯在室温下顺利进行了DA /碳环化级联环化反应，并在一锅中提供了高收率和高非对映选择性的三环环化产物。三环环化产物已成​​功地用作（±）-Platensimycin和（±）-platencin形式合成的常用中间体。
• A controlled selective synthesis of dihydropyrans through tandem reaction of alkynes with diazo compounds
  作者：Junxiang Min、Guangyang Xu、Jiangtao Sun

  DOI：10.1039/c7cc01616f

  日期：——

  A controlled synthesis of dihydropyrans via sequential reaction of allenoate formation and intramolecular oxo-Michael addition has been achieved.

  通过烯尿酸酯形成和分子内氧代-迈克尔加成的顺序反应，实现了对二氢吡喃的受控合成。
• A Bifunctional Lewis Acid Induced Cascade Cyclization to the Tricyclic Core of <i>ent</i>-Kaurenoids and Its Application to the Formal Synthesis of (±)-Platensimycin
  作者：Lizhi Zhu、Yejian Han、Guangyan Du、Chi-Sing Lee

  DOI：10.1021/ol3033412

  日期：2013.2.1

  A mild and efficient bifunctional Lewis acid induced cascade cyclization reaction has been developed for construction of the tricyclic core of ent-kaurenolds. With ZnBr2 as the bifunctional Lewis acid, a series of substituted enones and dienes underwent cascade cyclization smoothly at room temperature and provided the tricyclic products in one pot with good yields (75-91%) and high diastereoselectivity. The cyclized product has been successfully employed for the formal synthesis of (+/-)-platenslmycln.
• Ligand, solvent, and deuterium isotope effects in Mn(III)-based oxidative free-radical cyclizations
  作者：Barry B. Snider、Bridget A. McCarthy

  DOI：10.1021/jo00075a015

  日期：1993.11

  Oxidation of beta-keto ester 1 with Mn(Pic)3 and Cu(OAc)2 affords bicycloalkane 8, not the expected alkene 7, which is formed in high yield with Mn(OAc)3 and Cu(OAc)2. A series of control experiments established that the most likely explanation for this observation is that Mn(PiC)2, but not Mn(OAC)2, reacts with the bicyclic radical 5 more rapidly than Cu(OAc)2 does. These studies also indicate the potential for improved yields from oxidative free-radical cyclization of deuterated substrates. For instance, reaction of beta-keto ester 1-d with 2 equiv of Mn(OAc)3 and no Cu(OAC)2 affords 65% of 8, whereas beta-keto ester 1 provides only 22% of 8 under the same conditions. Large kinetic isotope effects change the nature of the termination step and prevent the formation of acyclic radical 3 by intermolecular hydrogen transfer. Solvent and ligand effects on the oxidation of beta-keto ester 1, malonate 14, and acetylenic beta-keto ester 25 are described.
• Synthesis of 2,5-Disubstituted Furans via Palladium-Catalyzed Annulation of Alkyl 3-Oxo-6-heptynoates
  作者：Sandro Cacchi、Giancarlo Fabrizi、Leonardo Moro

  DOI：10.1021/jo962386v

  日期：1997.8.1

  The reaction of the readily available alkyl 3-oxo-6-heptynoates with aryl halides in the presence of K2CO3 and catalytic amounts of Pd(PPh3)(4) at 100 degrees C provides a valuable new route to 2,5-disubstituted furans 3. Most probably, the furan ring is generated through an annulation reaction promoted by sigma-arylpalladium complexes generated in situ and involving the nucleophilic attack of the ketonic oxygen across the carbon-carbon triple bond coordinated to palladium, followed by the base-catalyzed isomerization of the resultant stereoisomeric 2,5-dialkylidenetetrahydrofuran intermediates 4 and 5. The reaction is highly chemoselective. No evidence was obtained of carboannulation products. The reaction temperature has proven to be crucial for the success of the methodology. The K2CO3:alkyne ratio also affects the reaction outcome. The highest yields of furan derivatives have been obtained with aryl halides containing electron-withdrawing substituents, very likely because the higher acidity of the methylene protons of 4 and 5 favors the isomerization step. Extension of the methodology to methyl 3-oxo-7-substituted-6-heptynoates leads to the formation of 2,5-disubstituted furans containing a branched side chain. The presence of an alkyl substituent on the C-2 of the staring alkyne, however, seems to prevent the isomerization step. Treatment of ethyl 2-methyl-3-oxo-6-heptynoate under our standard conditions produced in fact the 2,5-dialkylidene derivative 5p in 42% yield, and no evidence of the corresponding furan derivative was attained.