dimethyl 2,3-dimethylpentylidinemalonate | 252950-60-0

• 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: dimethyl 2,3-dimethylpentylidinemalonate
• CAS: 252950-60-0
• 化学式: C₁₂H₂₀O₄
• 分子量: 228.288
• InChiKey: PLCADORGWRGAIO-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.94
• 重原子数：
  16.0
• 可旋转键数：
  5.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  52.6
• 氢给体数：
  0.0
• 氢受体数：
  4.0

反应信息

• 作为反应物：
  描述：

  dimethyl 2,3-dimethylpentylidinemalonate 在 三氟乙酸 作用下， 以 乙醇 、 二氯甲烷 为溶剂， 反应 2.0h， 生成 (+/-)-2,8-dimethyl-2-(1-methylpropyl)-2,3-dihydro-4H-furo[2,3-d]pyrido[1,2-a]pyrimidin-4-one
  参考文献：
  名称：

  Electro-organic Reactions. Part 49. The Synthesis and Stereoselective Electrochemical Hydroxylation of 2,3-Dihydro-4H-furo[2,3-d]pyrido[1,2-a]pyrimidin-4-ones.

  摘要：

  Attempted electrochemical (anodic) hydroxylation of pyridopyrimidine derivatives in the pyridine ring, using trifluoroacetate as nucleophile, fails because enol forms predominate which undergo anodic C-O coupling. Substitution, aimed at precluding enolisation, led to an alternative tautomerisation to 8-methyl-3-alkylmethylene-4H-pyrido [1,2-a]pyrimidine-2,4-diones which in acidic solution are converted into the title compounds. The 8-methyl-2,3-dihydro-4H-furo[2,3-d]pyrido[1,2-a]pyrimidine-4-ones are novel and have been fully characterised by spectroscopy and X-ray crystallography. They are electroactive and are oxidised anodically in trifluoroacetic acid-dichloromethane-triethylammonium trifluoroacetate solutions to give the corresponding 3-hydroxy derivatives in good yield. Several examples of this allylic substitution reaction are presented; for cases disubstituted at the 2-position (R-1,R-2) diastereoselective hydroxylation with d.e. ca. 50% (3:1) is observed in which preferential nucleophilic attack on the stabilised intermediate allylic cation occurs at the least hindered face. The stereochemistry of the 3-hydroxy derivatives was assigned by NOE experiments.

  DOI：

  10.3891/acta.chem.scand.53-0901
• 作为产物：
  描述：

  2，3-二甲基戊醛 、 丙二酸二甲酯 在 哌啶乙酸盐 作用下， 以 苯 为溶剂， 以70%的产率得到dimethyl 2,3-dimethylpentylidinemalonate
  参考文献：
  名称：

  Electro-organic Reactions. Part 49. The Synthesis and Stereoselective Electrochemical Hydroxylation of 2,3-Dihydro-4H-furo[2,3-d]pyrido[1,2-a]pyrimidin-4-ones.

  摘要：

  Attempted electrochemical (anodic) hydroxylation of pyridopyrimidine derivatives in the pyridine ring, using trifluoroacetate as nucleophile, fails because enol forms predominate which undergo anodic C-O coupling. Substitution, aimed at precluding enolisation, led to an alternative tautomerisation to 8-methyl-3-alkylmethylene-4H-pyrido [1,2-a]pyrimidine-2,4-diones which in acidic solution are converted into the title compounds. The 8-methyl-2,3-dihydro-4H-furo[2,3-d]pyrido[1,2-a]pyrimidine-4-ones are novel and have been fully characterised by spectroscopy and X-ray crystallography. They are electroactive and are oxidised anodically in trifluoroacetic acid-dichloromethane-triethylammonium trifluoroacetate solutions to give the corresponding 3-hydroxy derivatives in good yield. Several examples of this allylic substitution reaction are presented; for cases disubstituted at the 2-position (R-1,R-2) diastereoselective hydroxylation with d.e. ca. 50% (3:1) is observed in which preferential nucleophilic attack on the stabilised intermediate allylic cation occurs at the least hindered face. The stereochemistry of the 3-hydroxy derivatives was assigned by NOE experiments.

  DOI：

  10.3891/acta.chem.scand.53-0901