methyl (3R)-3-ethyl-4-methylpentanoate | 79194-61-9

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: methyl (3R)-3-ethyl-4-methylpentanoate
• 英文别名: (R)-(-)-methyl 3-ethyl-4-methylpentanoate；Methyl (r)-3-ethyl-4-methylpentanoate
• CAS: 79194-61-9
• 化学式: C₉H₁₈O₂
• 分子量: 158.241
• InChiKey: TWZULJKZBGIFOI-MRVPVSSYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.7
• 重原子数：
  11
• 可旋转键数：
  5
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.89
• 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：

  (20S)-20-(iodomethyl)-4α-methyl-5α-pregnane 、 methyl (3R)-3-ethyl-4-methylpentanoate 生成 (20R,23ξ,24S)-4α-methyl-5α-stigmastane-23-carboxylic acid
  参考文献：
  名称：

  Synthesis of biological markers in fossil fuels. 7. Selected diastereomers of 4.alpha.-methyl-5.alpha.-stigmastane and 5.alpha.-dinosterane

  摘要：

  Efficient routes for the preparation of selected C-23 and C-24 diastereomers of the C30 biological markers 4alpha-methyl-5alpha-stigmastane (1) and 5alpha-dinosterane (2) involved the alkylation of 20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with either saturated or alpha,beta-unsaturated esters. The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (3R)-3-ethyl-4-methylpentanoate furnished methyl (20R,23zeta,24S)-4alpha-methyl-5alpha-stigmastane-23-carboxylate, and a subsequent decarbomethoxylation provided (20R,24R)-l. The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (3S)-3,4-dimethylpentanoate led to methyl (20R,23zeta,24R)-4alpha,24-dimethyl-5alpha-cholestane-23-carboxylate, and the reduction of this mixture provided principally (20R,23S,24R)-5alpha-dinosteran-29-ol. The further reduction of the mesylate of this isomer secured (20R,23S,24R)-5alpha-dinosterane (2a). The application of the same sequence of reactions using methyl (3R)-3,4-dimethylpentanoate led principally to (20R,23R,24S)-5alpha-dinosterane (2d). The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (2zeta)-3,4-dimethyl-2-pentanoate and a subsequent reduction of the ester provided a separable mixture of (20R,23R)- and (20R,23S)-5alpha-dinoster-24-(28)-en-29-ol in a 2.4:1 ratio. The conversion of (20R,23R)-5alpha-dinoster-24(28)-en-29-ol to the corresponding tert-butyldimethylsilyl ether, reduction of the DELTA24(28) bond with hydrogen over platinum oxide, and deprotection gave principally (20R,23R,24R)-5alpha-dinosteran-29-ol. The further reduction of this alcohol provided (20R,23R,24R)-5alpha-dinosterane (2b). The application of the same sequence of reactions to (20R,23S)-5alpha-dinoster-24(28)-en-29-ol provided (20R,23S,24S)-5alpha-dinosterane (2c). Diastereoselectivity at the C-23 position in these ester alkylations was examined as a function of stereochemistry at both the C-20 and C-24 positions.

  DOI：

  10.1021/jo00064a039
• 作为产物：
  描述：

  methyl 4-methyl-2-pentenoate 、 乙基溴化镁 在 tetrakis(acetonitrile)copper(I)tetrafluoroborate 、 C₄₄H₅₂FeP₂ 作用下， 以 二氯甲烷 、 甲基叔丁基醚 为溶剂， 以86%的产率得到methyl (3R)-3-ethyl-4-methylpentanoate
  参考文献：
  名称：

  手性尿素型胺：实用合成，配体发展和不对称催化。

  摘要：

  乌吉胺已成为具有中心/平面手性的手性配体设计的一种优先的手性骨架，这种配体在各种不对称催化中已显示出巨大的成功。但是，目前获得对映纯Ugi胺非常繁琐，并且在很大程度上取决于光学分辨率，这在一定程度上阻碍了其实际应用。在本文中，我们介绍了通过Ir催化的级联烯丙基化/ 2-氮杂-Cope重排，然后进行氨基交换和Pd / C催化的一锅加氢/还原反应，轻松地不对称合成带有长碳链的富含对映体的Ugi型胺胺化。该方案很容易扩大规模，并且已在20 g规模的（S来自市售试剂的（-Ugi-type）尿素，> ee> 99％，总收率> 70％，分四个步骤进行一次硅胶短柱纯化。（S，R p）-PPFA型和（S，R p）-Josiphos型配体，很容易从获得的Ugi型胺制备，在几种Cu（I）催化下表现出更高或相当的不对称诱导和催化功效不对称反应，表明易于获得的Ugi型胺在配体/催化剂设计中的应用潜力很大。

  DOI：

  10.1021/acscatal.0c04077

文献信息

• Cu(I) Tol-BINAP-Catalyzed Enantioselective Michael Reactions of Grignard Reagents and Unsaturated Esters
  作者：Shun-Yi Wang、Shun-Jun Ji、Teck-Peng Loh

  DOI：10.1021/ja0666046

  日期：2007.1.1

  A highly efficient regio- and enantioselective catalytic asymmetric addition of Grignard regeants to α,β-unsaturated esters promoted by the CuI-Tol-BINAP system is described.

  描述了由 CuI-Tol-BINAP 系统促进的格氏试剂向 α,β-不饱和酯的高效区域和对映选择性催化不对称加成。
• Synthesis of biological markers in fossil fuels. 7. Selected diastereomers of 4.alpha.-methyl-5.alpha.-stigmastane and 5.alpha.-dinosterane
  作者：Ivan Stoilov、Ewa Kolaczkowska、David S. Watt、Jan St. Pyrek、Robert M. K. Carlson、Frederick J. Fago、J. Michael Moldowan

  DOI：10.1021/jo00064a039

  日期：1993.6

  Efficient routes for the preparation of selected C-23 and C-24 diastereomers of the C30 biological markers 4alpha-methyl-5alpha-stigmastane (1) and 5alpha-dinosterane (2) involved the alkylation of 20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with either saturated or alpha,beta-unsaturated esters. The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (3R)-3-ethyl-4-methylpentanoate furnished methyl (20R,23zeta,24S)-4alpha-methyl-5alpha-stigmastane-23-carboxylate, and a subsequent decarbomethoxylation provided (20R,24R)-l. The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (3S)-3,4-dimethylpentanoate led to methyl (20R,23zeta,24R)-4alpha,24-dimethyl-5alpha-cholestane-23-carboxylate, and the reduction of this mixture provided principally (20R,23S,24R)-5alpha-dinosteran-29-ol. The further reduction of the mesylate of this isomer secured (20R,23S,24R)-5alpha-dinosterane (2a). The application of the same sequence of reactions using methyl (3R)-3,4-dimethylpentanoate led principally to (20R,23R,24S)-5alpha-dinosterane (2d). The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (2zeta)-3,4-dimethyl-2-pentanoate and a subsequent reduction of the ester provided a separable mixture of (20R,23R)- and (20R,23S)-5alpha-dinoster-24-(28)-en-29-ol in a 2.4:1 ratio. The conversion of (20R,23R)-5alpha-dinoster-24(28)-en-29-ol to the corresponding tert-butyldimethylsilyl ether, reduction of the DELTA24(28) bond with hydrogen over platinum oxide, and deprotection gave principally (20R,23R,24R)-5alpha-dinosteran-29-ol. The further reduction of this alcohol provided (20R,23R,24R)-5alpha-dinosterane (2b). The application of the same sequence of reactions to (20R,23S)-5alpha-dinoster-24(28)-en-29-ol provided (20R,23S,24S)-5alpha-dinosterane (2c). Diastereoselectivity at the C-23 position in these ester alkylations was examined as a function of stereochemistry at both the C-20 and C-24 positions.
• Chiral Ugi-Type Amines: Practical Synthesis, Ligand Development, and Asymmetric Catalysis
  作者：Wu-Wei Dong、Yi-Nan Li、Xin Chang、Chong Shen、Chun-Jiang Wang

  DOI：10.1021/acscatal.0c04077

  日期：2020.11.6

  privileged chiral skeleton for chiral ligand design bearing central/planar chirality, and such ligands have exhibited tremendous success in various asymmetric catalysis. However, the current access to enantiopure Ugi’s amine is quite tedious and relies heavily on optical resolution, which impedes its practical applications, to some extent. Herein, we present a facile asymmetric synthesis of enantioenriched

  乌吉胺已成为具有中心/平面手性的手性配体设计的一种优先的手性骨架，这种配体在各种不对称催化中已显示出巨大的成功。但是，目前获得对映纯Ugi胺非常繁琐，并且在很大程度上取决于光学分辨率，这在一定程度上阻碍了其实际应用。在本文中，我们介绍了通过Ir催化的级联烯丙基化/ 2-氮杂-Cope重排，然后进行氨基交换和Pd / C催化的一锅加氢/还原反应，轻松地不对称合成带有长碳链的富含对映体的Ugi型胺胺化。该方案很容易扩大规模，并且已在20 g规模的（S来自市售试剂的（-Ugi-type）尿素，> ee> 99％，总收率> 70％，分四个步骤进行一次硅胶短柱纯化。（S，R p）-PPFA型和（S，R p）-Josiphos型配体，很容易从获得的Ugi型胺制备，在几种Cu（I）催化下表现出更高或相当的不对称诱导和催化功效不对称反应，表明易于获得的Ugi型胺在配体/催化剂设计中的应用潜力很大。