ethyl (R)-2-acetyl-2-ethyl-4-methylpentanoate | 500905-33-9

• 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 (R)-2-acetyl-2-ethyl-4-methylpentanoate
• 英文别名: ethyl (R)-2-ethyl-2-isobutylacetoacetate；ethyl (2R)-2-acetyl-2-ethyl-4-methylpentanoate
• CAS: 500905-33-9
• 化学式: C₁₂H₂₂O₃
• 分子量: 214.305
• InChiKey: ODOSTGNYEAGFNL-GFCCVEGCSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.58
• 重原子数：
  15.0
• 可旋转键数：
  6.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  43.37
• 氢给体数：
  0.0
• 氢受体数：
  3.0

反应信息

• 作为反应物：
  描述：

  ethyl (R)-2-acetyl-2-ethyl-4-methylpentanoate 在 盐酸 、 sodium azide 、 甲烷磺酸 、 1-(3-二甲基氨基丙基)-3-乙基碳二亚胺 作用下， 以 氯仿 、 乙腈 为溶剂， 反应 288.0h， 生成 ethyl trifluoroacetyl-(S)-α-ethylleucyl-diethylglycyl-diethylglycyl-diethylglycyl-diethylglycinate
  参考文献：
  名称：

  Conformation of Peptides Containing a Chiral -Ethylated ,-Disubstituted -Amino Acid: (S)--Ethylleucine (=(2S)-2-Amino-2-ethyl-4-methylpentanoic Acid) within Sequences of Dimethylglycine and Diethylglycine Residues

  摘要：

  An optically active (S)-alpha-ethylleucine ((S)-alphaEtLeu) as a chiral alpha-ethylated alpha,alpha-disubstituted alpha-amino acid was synthesized by means of a chiral acetal auxiliary of (R,R)-cyclohexane-1,2-diol. The chiral alpha-ethylated alpha,alpha-disubstituted amino acid (S)-alphaEtLeu was introduced into the peptides constructed from 2aminoisobutyric acid (= dimethylglycine, Aib), and also into the peptide prepared from diethylglycine (Deg). The X-ray crystallographic analysis revealed that both right-handed (P) and left-handed (M) 3(10)-helical structures exist in the solid state of CF3CO-(Aib)(2)-[(S)-alphaEtLeu]-(Aib)(2)-OEt (14) and CF3CO-[(S)-alphaEtLeu]-(Deg)(4)-OEt (18), respectively. The IR, CD, and H-1-NMR spectra indicated that the dominant conformation of pentapeptides 14 and CF3CO-[(S)-alphaEtLeu]-(Aib)(4)-OEt (16) in solution is a 3(10)-helical structure, and that of 18 in solution is a planar C-5 conformation. The conformation of peptides was also studied by molecular-mechanics calculations.

  DOI：

  10.1002/1522-2675(200210)85:10<3197::aid-hlca3197>3.0.co;2-y
• 作为产物：
  描述：

  ethyl (2RS)-3,3-[(1R,2R)-cyclohexane-1,2-dioxy]-2-ethylbutanoate 在 六甲基磷酰三胺 、 三氟化硼乙醚 、 lithium diisopropyl amide 作用下， 以 四氢呋喃 、 乙醇 、 正己烷 、 水 为溶剂， 反应 13.5h， 生成 ethyl (R)-2-acetyl-2-ethyl-4-methylpentanoate
  参考文献：
  名称：

  Conformation of Peptides Containing a Chiral -Ethylated ,-Disubstituted -Amino Acid: (S)--Ethylleucine (=(2S)-2-Amino-2-ethyl-4-methylpentanoic Acid) within Sequences of Dimethylglycine and Diethylglycine Residues

  摘要：

  An optically active (S)-alpha-ethylleucine ((S)-alphaEtLeu) as a chiral alpha-ethylated alpha,alpha-disubstituted alpha-amino acid was synthesized by means of a chiral acetal auxiliary of (R,R)-cyclohexane-1,2-diol. The chiral alpha-ethylated alpha,alpha-disubstituted amino acid (S)-alphaEtLeu was introduced into the peptides constructed from 2aminoisobutyric acid (= dimethylglycine, Aib), and also into the peptide prepared from diethylglycine (Deg). The X-ray crystallographic analysis revealed that both right-handed (P) and left-handed (M) 3(10)-helical structures exist in the solid state of CF3CO-(Aib)(2)-[(S)-alphaEtLeu]-(Aib)(2)-OEt (14) and CF3CO-[(S)-alphaEtLeu]-(Deg)(4)-OEt (18), respectively. The IR, CD, and H-1-NMR spectra indicated that the dominant conformation of pentapeptides 14 and CF3CO-[(S)-alphaEtLeu]-(Aib)(4)-OEt (16) in solution is a 3(10)-helical structure, and that of 18 in solution is a planar C-5 conformation. The conformation of peptides was also studied by molecular-mechanics calculations.

  DOI：

  10.1002/1522-2675(200210)85:10<3197::aid-hlca3197>3.0.co;2-y

文献信息

• Asymmetric Synthesis of α,α-Disubstituted α-Amino Acids Using (<i>S</i>,<i>S</i>)-Cyclohexane-1,2-diol as a Chiral Auxiliary
  作者：Masakazu Tanaka、Makoto Oba、Koichi Tamai、Hiroshi Suemune

  DOI：10.1021/jo001423m

  日期：2001.4.1

  Diastereoselective alkylation of ethyl 2-methyl- and/or 2-ethylacetoacetates using the (S,S)cyclohexane-1,2-diol as an acetal chiral auxiliary afforded enol ethers (2a-f and 5a-f) of 92 - > 95% de in 31-70% yields. Removal of the cyclohexane-l,2-diol with BF3-OEt2 afforded beta -keto esters (3 and 6) bearing a chiral quaternary carbon. The beta -keto esters could be easily converted into optically active alpha -methylated and/or alpha -ethylated alpha,alpha -disubstituted amino acids (12 and 13) in 21-99% yields using Schmidt rearrangement.