(+)-3(S)-ethyl-2-methylenecyclohexanone | 124482-32-2

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (+)-3(S)-ethyl-2-methylenecyclohexanone
• 英文别名: (3S)-ethyl-2-methylene-cyclohexanone；(3S)-3-ethyl-2-methylidenecyclohexan-1-one
• CAS: 124482-32-2
• 化学式: C₉H₁₄O
• 分子量: 138.21
• InChiKey: BXDZLBBXQKADPG-QMMMGPOBSA-N

物化性质

• 沸点：
  212.6±10.0 °C(Predicted)
• 密度：
  0.91±0.1 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.4
• 重原子数：
  10
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  17.1
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  甲醇 、 (+)-3(S)-ethyl-2-methylenecyclohexanone 生成 methyl (5S)-5-ethylhept-6-enoate
  参考文献：
  名称：

  串联对映选择性共轭加成-环丙烷化。应用于天然产物合成。

  摘要：

  开发了串联不对称共轭加成-环丙烷化反应，其中在有效的一锅反应中将环状或线性烯酮转化为TMS保护的3-取代-环丙醇。然后将这些化合物选择性裂解，得到α-甲基-β-烷基酮，α-亚甲基-烯酮或扩链的γ-烷基-烯酮。该方法学应用于（-）-（S，S）-克拉维林A和（+）-（R，S）-异克拉维林的正式全合成。

  DOI：

  10.1021/jo026262w
• 作为产物：
  描述：

  2-(硝基甲基)-环己-1-烯-3-酮 在 lithium bromide 作用下， 以 乙腈 为溶剂， 反应 2.17h， 生成 (+)-3(S)-ethyl-2-methylenecyclohexanone
  参考文献：
  名称：

  Asymmetric synthesis of 3-substituted 2-exo-methylenealkanones by addition-elimination reaction using a chiral leaving group and organometallic nucleophiles

  摘要：

  A novel diastereodifferentiating addition-elimination reaction of (S)-2-[[2-(methoxymethyl)-1-pyrrolidinyl]methyl]-2-alken-1-ones with organometallic reagents such as organocuprates and organozincates afforded optically active 3-substituted 2-methylenealkanones with high enantiomeric purity. The enantiomeric excess (ee) of the products in this asymmetric induction reaction involving 1,5-transfer of stereogenicity was highly dependent on the structure of the enone substrates and the type of organometallic reagents, chiral auxiliaries, and added Lewis acids: (i) the use of lithium diorganocuprates (R2CuLi) led to the highest ee's, (ii) in the reaction with R2CuLi the ee decreased in the following order by varying their structure of the main framework of the enones, cycloheptenones (96-97% ee) > cyclohexenones (95% ee) > cyclopentenones (82-85% ee) > acyclic enones (55-70% ee), (iii) the addition of LiBr as the external Lewis acid in the reaction with R2CuLi did not affect the ee, whereas that of ZnBr2 or MgBr2 decreased the ee by 5% or considerably more, respectively, and (iv) the existence of the methoxy oxygen atom in the chiral auxiliary was essential to achieve high ee's. The origin of the observed high and low ee's was rationalized by considering plausible transition state models.

  DOI：

  10.1021/jo00044a026

文献信息

• Tandem Asymmetric Conjugate Addition−Silylation of Enantiomerically Enriched Zinc Enolates. Synthetic Importance and Mechanistic Implications
  作者：Oliver Knopff、Alexandre Alexakis

  DOI：10.1021/ol026644o

  日期：2002.10.1

  cyclic and acyclic enones, could be trapped, quantitatively, as silyl enol ethers with TMSOTf in apolar solvents or with TMSCI and NEt3. These enantiomerically enriched silyl enol ethers were submitted to four synthetic transformations to show their synthetic utility. The zinc enolates obtained from acyclic enones were found to be configurationally stable, as shown by the stereochemistry of the silyl

  [化学式：见正文]烯醇化锌是由铜催化的将二烷基锌试剂对环和无环烯酮加成铜的对映选择性共轭物而得到的，它可以被定量捕集，如甲硅烷基烯醇醚与TMSOTf在非极性溶剂中或与TMSCI和NEt3。这些对映体富集的甲硅烷基烯醇醚进行了四个合成转化，以显示其合成效用。如甲硅烷基烯醇醚的立体化学所示，发现从无环烯酮获得的烯醇锌是构型稳定的。
• Asymmetric synthesis of 3-substituted-2-exo-methylenecyclohexanones via 1,5-diastereoselection by using a chiral amine
  作者：Rui Tamura、Kenichiro Watabe、Hitoshi Katayama、Hitomi Suzuki、Yukio Yamamoto

  DOI：10.1021/jo00289a003

  日期：1990.1
• TAMURA, RUI;WATABE, KEN-ICHIRO;KATAYAMA, HITOSHI;SUZUKI, HITOMI;YAMAMOTO,+, J. ORG. CHEM., 55,(1990) N, C. 408-410
  作者：TAMURA, RUI、WATABE, KEN-ICHIRO、KATAYAMA, HITOSHI、SUZUKI, HITOMI、YAMAMOTO,+

  DOI：——

  日期：——
• Asymmetric synthesis of 3-substituted 2-exo-methylenealkanones by addition-elimination reaction using a chiral leaving group and organometallic nucleophiles
  作者：Rui Tamura、Kenichiro Watabe、Noboru Ono、Yukio Yamamoto

  DOI：10.1021/jo00044a026

  日期：1992.8

  A novel diastereodifferentiating addition-elimination reaction of (S)-2-[[2-(methoxymethyl)-1-pyrrolidinyl]methyl]-2-alken-1-ones with organometallic reagents such as organocuprates and organozincates afforded optically active 3-substituted 2-methylenealkanones with high enantiomeric purity. The enantiomeric excess (ee) of the products in this asymmetric induction reaction involving 1,5-transfer of stereogenicity was highly dependent on the structure of the enone substrates and the type of organometallic reagents, chiral auxiliaries, and added Lewis acids: (i) the use of lithium diorganocuprates (R2CuLi) led to the highest ee's, (ii) in the reaction with R2CuLi the ee decreased in the following order by varying their structure of the main framework of the enones, cycloheptenones (96-97% ee) > cyclohexenones (95% ee) > cyclopentenones (82-85% ee) > acyclic enones (55-70% ee), (iii) the addition of LiBr as the external Lewis acid in the reaction with R2CuLi did not affect the ee, whereas that of ZnBr2 or MgBr2 decreased the ee by 5% or considerably more, respectively, and (iv) the existence of the methoxy oxygen atom in the chiral auxiliary was essential to achieve high ee's. The origin of the observed high and low ee's was rationalized by considering plausible transition state models.
• Tandem Enantioselective Conjugate Addition−Cyclopropanation. Application to Natural Products Synthesis
  作者：Alexandre Alexakis、Sébastien March

  DOI：10.1021/jo026262w

  日期：2002.12.1

  A tandem asymmetric conjugate addition-cyclopropanation was developed, in which a cyclic or linear enone was converted to a TMS-protected 3-substituted-cyclopropanol in an efficient one-pot reaction. These compounds were then selectively cleaved to yield alpha-methyl-beta-alkyl ketones, alpha-methylene-enones, or chain extended gamma-alkyl-enones. This methodology was applied to the formal total synthesis

  开发了串联不对称共轭加成-环丙烷化反应，其中在有效的一锅反应中将环状或线性烯酮转化为TMS保护的3-取代-环丙醇。然后将这些化合物选择性裂解，得到α-甲基-β-烷基酮，α-亚甲基-烯酮或扩链的γ-烷基-烯酮。该方法学应用于（-）-（S，S）-克拉维林A和（+）-（R，S）-异克拉维林的正式全合成。