2-pentanone enolate | 184168-99-8

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 2-pentanone enolate
• 英文别名: enolate ion from 2-pentanone；Pent-1-en-2-olate
• CAS: 184168-99-8
• 化学式: C₅H₉O
• 分子量: 85.1259
• InChiKey: RTJBLRZRSVEQRH-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  2.3
• 重原子数：
  6
• 可旋转键数：
  2
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.6
• 拓扑面积：
  23.1
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  二甲基二硫 、 2-pentanone enolate 生成 methanethiolate
  参考文献：
  名称：

  Anion Structure Determination in the Gas Phase:  Chemical Reactivity as a Probe

  摘要：

  In the gas phase, the discrimination between two isomeric anion structures is a challenge that requires different solutions for different applications. The anionic oxy-Cope rearrangement involves the rearrangement of an alkoxide to an isomeric enolate; the mechanistic study of such a process in the gas phase requires a simple and selective probe process. Using a flowing afterglow mass spectrometer, we have examined the utility and limitations of using chemical reactivity to discriminate between alkoxides and enolates in the gas phase. A series of alkoxides and enolates were allowed to react with three chemical probe reagents: methanol-O-d, methyl nitrite, and dimethyl disulfide. Quantitative and qualitative characterization of each probe reagent reveals the especially broad and flexible utility of dimethyl disulfide as a chemical probe. Dimethyl disulfide is a selective reagent with ambident behavior that reacts efficiently with all anions studied and fully capitalizes on the structure/reactivity differences between alkoxides and enolates. Alkoxides behave as classical ''hard bases'' when allowed to react with dimethyl disulfide, effecting elimination across the C-S bond, whereas enolates, ''soft bases'', attack at sulfur. Methyl nitrite is also a selective ambident probe reagent but, due to its particularly slow reaction with enolates, is useful only in conjunction with a more reliable probe such as dimethyl disulfide. Methanol-O-d, for a variety of reasons detailed in the paper, is unsuitable as a chemical probe reagent for the unequivocal discernment between alkoxides and enolates.

  DOI：

  10.1021/jo961463j
• 作为产物：
  描述：

  2-戊酮 在 hydroxide 作用下， 生成 2-pentanone enolate 、 enolate ion from 2-pentanone
  参考文献：
  名称：

  Fragmentation reactions of the enolate ions of 2-pentanone

  摘要：

  AbstractThe reaction of [OH]− with 2‐pentanone produces two enolate ions, [CH3CH2CH2COCH2]− and [CH3COCHCH2CH3]−, by proton abstraction from C(1) and C(3), respectively. Using deuterium isotopic labelling the fragmentation reactions of each enolate have been delineated for collisional activation at both high (8 keV) and low (5–100 eV) collisional energies. The primary enolate ion fragments mainly by elimination of ethene. Two mechanisms operate: elimination of C(4) and C(5) with hydrogen migration from C(5), and elimination of C(3) and C(4) with migration of the C(5) methyl group. Minor fragmentation of the primary enolate also occurs by elimination of propane and elimination of C2H5; the latter reaction involves specifically the terminal ethyl group. The secondary enolate ion fragments mainly by loss of H2 and by elimination of CH4; for the latter reaction four different pathways are operative. Minor elimination of ethene also is observed involving migration of a C(5) hydrogen to C(3) and elimination of C(4) and C(5) as ethene.

  DOI：

  10.1002/oms.1210240206

文献信息

• Carbanion rearrangements. Collision-induced dissociations of the enolate ion of heptan-4-one
  作者：Michael B. Stringer、John H. Bowie、John L. Holmes

  DOI：10.1021/ja00274a005

  日期：1986.7

  Le mecanisme de formation des principaux ions negatifs obtenus dans le schema de fragmentation de l'ion du titre est etudie en utilisant une serie de composes marques D et 13 C

  Le mecanisme deformation des principaux ions negatifs obtenus dans le schema de fragmentation de l'ion du titre est etudie en utilisant une serie de composes marques D et 13 C
• Anion Structure Determination in the Gas Phase:  Chemical Reactivity as a Probe
  作者：Jeehiun K. Lee、Joseph J. Grabowski

  DOI：10.1021/jo961463j

  日期：1996.1.1

  In the gas phase, the discrimination between two isomeric anion structures is a challenge that requires different solutions for different applications. The anionic oxy-Cope rearrangement involves the rearrangement of an alkoxide to an isomeric enolate; the mechanistic study of such a process in the gas phase requires a simple and selective probe process. Using a flowing afterglow mass spectrometer, we have examined the utility and limitations of using chemical reactivity to discriminate between alkoxides and enolates in the gas phase. A series of alkoxides and enolates were allowed to react with three chemical probe reagents: methanol-O-d, methyl nitrite, and dimethyl disulfide. Quantitative and qualitative characterization of each probe reagent reveals the especially broad and flexible utility of dimethyl disulfide as a chemical probe. Dimethyl disulfide is a selective reagent with ambident behavior that reacts efficiently with all anions studied and fully capitalizes on the structure/reactivity differences between alkoxides and enolates. Alkoxides behave as classical ''hard bases'' when allowed to react with dimethyl disulfide, effecting elimination across the C-S bond, whereas enolates, ''soft bases'', attack at sulfur. Methyl nitrite is also a selective ambident probe reagent but, due to its particularly slow reaction with enolates, is useful only in conjunction with a more reliable probe such as dimethyl disulfide. Methanol-O-d, for a variety of reasons detailed in the paper, is unsuitable as a chemical probe reagent for the unequivocal discernment between alkoxides and enolates.
• Fragmentation reactions of the enolate ions of 2-pentanone
  作者：Allen Donnelly、Swapan Chowdhury、Alex. G. Harrison

  DOI：10.1002/oms.1210240206

  日期：1989.2

  AbstractThe reaction of [OH]− with 2‐pentanone produces two enolate ions, [CH3CH2CH2COCH2]− and [CH3COCHCH2CH3]−, by proton abstraction from C(1) and C(3), respectively. Using deuterium isotopic labelling the fragmentation reactions of each enolate have been delineated for collisional activation at both high (8 keV) and low (5–100 eV) collisional energies. The primary enolate ion fragments mainly by elimination of ethene. Two mechanisms operate: elimination of C(4) and C(5) with hydrogen migration from C(5), and elimination of C(3) and C(4) with migration of the C(5) methyl group. Minor fragmentation of the primary enolate also occurs by elimination of propane and elimination of C2H5; the latter reaction involves specifically the terminal ethyl group. The secondary enolate ion fragments mainly by loss of H2 and by elimination of CH4; for the latter reaction four different pathways are operative. Minor elimination of ethene also is observed involving migration of a C(5) hydrogen to C(3) and elimination of C(4) and C(5) as ethene.