5-methoxy-2-methyl-4-propyl-1,3-oxazole | 607365-90-2

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑类
• 英文名称: 5-methoxy-2-methyl-4-propyl-1,3-oxazole
• 英文别名: 2-methyl-4-propyl-5-methoxyoxazole；5-Methoxy-2-methyl-4-propyloxazole
• CAS: 607365-90-2
• 化学式: C₈H₁₃NO₂
• 分子量: 155.197
• InChiKey: MMTXVCJJFXKQAX-UHFFFAOYSA-N

物化性质

• 沸点：
  201.9±20.0 °C(Predicted)
• 密度：
  1.000±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.2
• 重原子数：
  11
• 可旋转键数：
  3
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.62
• 拓扑面积：
  35.3
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  5-methoxy-2-methyl-4-propyl-1,3-oxazole 在 盐酸 作用下， 以 二氯甲烷 、 苯 为溶剂， 反应 27.0h， 生成 methyl (2RS,3RS)-2-(acetylamino)-3-hydroxy-4-methyl-2-propylpentanoate
  参考文献：
  名称：

  Synthesis of erythro-α-Amino β-hydroxy Carboxylic Acid Esters by Diastereoselective Photocycloaddition of 5-Methoxyoxazoles with Aldehydes

  摘要：

  A new photoaldol route to alpha-amino-beta-hydroxy carboxylic acid esters is initiated by the photocycloaddition of aromatic or aliphatic aldehydes to 5-methoxyoxazoles. The 4-unsubstituted 5-methyloxazole 1 gave the cycloadducts 8a-f in high yields and excellent exo-diastereoselectivities. Hydrolysis of 8a-f gives the N-acetyl alpha-amino-beta-hydroxy esters 9a-f, which could be subsequently converted into the corresponding Z-didehydro alpha-amino acids 10a-f. Quartenary alpha-amino-beta-hydroxy esters 12, 14, 16, 18, and 20, which are stable against dehydration, were obtained from the 4-alkylated 5-methoxyoxazoles 2-6, in most cases highly erythro-selective due to the high degree of stereocontrol (exo) at the photocycloaddition (to give 11, 13, 15, 17, and 19) level. The relative configurations of the N-acetyl alpha-amino-beta-hydroxy esters were determined by NMR spectroscopy and comparison with chiral pool-derived compounds as well as by X-ray structure determination of the ester 23, formed by hydrolysis of the cycloadduct 22, derived from photocycloaddition of propionaldehyde to the isoleucine-derived oxazole 21.

  DOI：

  10.1021/jo034830h
• 作为产物：
  描述：

  N-乙酰基正缬氨酸甲酯 在 五氯化磷 、 氢氧化钾 作用下， 以 氯仿 、 乙醚 为溶剂， 反应 0.5h， 生成 5-methoxy-2-methyl-4-propyl-1,3-oxazole
  参考文献：
  名称：

  5-甲氧基恶唑的光醛醇反应：α-氨基β-羟基羧酸衍生物的高度区域选择性和非对映选择性合成

  摘要：

  描述了具有叔（来自相应的甘氨酸等价物）或季 α-碳中心的 α-氨基 β-羟基羧酸衍生物的通用途径。关键反应是电子激发的羰基化合物（分别为芳香醛和脂肪醛）与恶唑的环加成反应。为了使产物水解更不稳定，在 C-5 位引入了甲氧基取代基，导致形成具有原酸酯亚结构的环加合物。光环加成，无论是三线态激发（芳香族）羰基化合物还是单线态激发（脂肪族）羰基化合物，都导致形成具有中等至极高外选择性的内型和外型非对映异构体的混合物。4-未取代的5-甲氧基恶唑1（甘氨酸等价物）以高产率和优异的非对映选择性得到[2+2]-加合物3a-β3f与醛2a-β2f。这些化合物的水解产生具有优选赤型 (S*,S*) 构型的 α-氨基 β-羟基酯 4a??4f...

  DOI：

  10.1139/v03-029

文献信息

• Stereoselective generation of vicinal stereogenic quaternary centers by photocycloaddition of 5-methoxy oxazoles to α-keto esters: synthesis of erythro β-hydroxy dimethyl aspartates
  作者：Axel G. Griesbeck、Samir Bondock、Johann Lex

  DOI：10.1039/b401990c

  日期：——

  The photocycloaddition of methyl pyruvate and methyl phenylglyoxylate, respectively, to 5-methoxy oxazoles bearing additional substituents at C-2 and C-4 leads to bicyclic oxetanes 2 and 3 with high to moderate (exo) diastereoselectivity that can be easily ring-opened to give bis-quaternary aspartic acid diester derivatives 4 and 5.

  甲基丙酮酸甲酯和甲基苯基乙二酮的光环加成反应，分别与在C-2和C-4位具有额外取代基的5-甲氧基噁唑反应，生成具有高到中等（外）二叠体选择性的双环氧杂烷2和3，这些化合物可以很容易地环开，生成双四元琥珀酸二酯衍生物4和5。
• Photocycloaddition of 5-Methoxyoxazoles to Aldehydes and ?-Keto Esters: A Comprehensive View on Stereoselectivity, Triplet Biradical Conformations, and Synthetic Applications of Paternò–Büchi Adducts
  作者：Axel G. Griesbeck、Samir Bondock

  DOI：10.1071/ch08168

  日期：——

  The photocycloaddition of carbonyl compounds (aldehydes and keto esters, respectively) with 5-methoxyoxazoles bearing substituents at C2 and C4 is described with respect to regio- and diastereoselectivity. In all cases the reactions proceed with excellent regioselectivity and with high to moderate (exo) diastereoselectivity independent of the nature of the excited carbonyl compound. The products can be easily ring-opened to give α-amino, β-hydroxy carboxylic acid derivatives.

  本研究介绍了羰基化合物（分别是醛和酮酯）与 C2 和 C4 上带有取代基的 5-甲氧基噁唑的光环加成反应的区域选择性和非对映选择性。在所有情况下，反应都具有极佳的区域选择性和高至中等的（外）非对映选择性，与激发的羰基化合物的性质无关。产物很容易开环，生成 α-氨基、β-羟基羧酸衍生物。
• Bondock, Samir; Latif, Ehab Abdel; Lex, Johann, Journal of Chemical Research, 2005, # 7, p. 422 - 426
  作者：Bondock, Samir、Latif, Ehab Abdel、Lex, Johann

  DOI：——

  日期：——
• Synthesis of <i>e</i><i>rythro</i>-α-Amino β-hydroxy Carboxylic Acid Esters by Diastereoselective Photocycloaddition of 5-Methoxyoxazoles with Aldehydes
  作者：Axel G. Griesbeck、Samir Bondock、Johann Lex

  DOI：10.1021/jo034830h

  日期：2003.12.1

  A new photoaldol route to alpha-amino-beta-hydroxy carboxylic acid esters is initiated by the photocycloaddition of aromatic or aliphatic aldehydes to 5-methoxyoxazoles. The 4-unsubstituted 5-methyloxazole 1 gave the cycloadducts 8a-f in high yields and excellent exo-diastereoselectivities. Hydrolysis of 8a-f gives the N-acetyl alpha-amino-beta-hydroxy esters 9a-f, which could be subsequently converted into the corresponding Z-didehydro alpha-amino acids 10a-f. Quartenary alpha-amino-beta-hydroxy esters 12, 14, 16, 18, and 20, which are stable against dehydration, were obtained from the 4-alkylated 5-methoxyoxazoles 2-6, in most cases highly erythro-selective due to the high degree of stereocontrol (exo) at the photocycloaddition (to give 11, 13, 15, 17, and 19) level. The relative configurations of the N-acetyl alpha-amino-beta-hydroxy esters were determined by NMR spectroscopy and comparison with chiral pool-derived compounds as well as by X-ray structure determination of the ester 23, formed by hydrolysis of the cycloadduct 22, derived from photocycloaddition of propionaldehyde to the isoleucine-derived oxazole 21.
• Photo aldol reactions with 5-methoxyoxazoles: Highly regio- and diastereoselective synthesis of α-amino β-hydroxy carboxylic acid derivatives
  作者：Axel G Griesbeck、Samir Bondock

  DOI：10.1139/v03-029

  日期：2003.6.1

  A versatile route to derivatives of α-amino β-hydroxy carboxylic acids, either with tertiary (from a corresponding glycine equivalent) or a quaternary α-carbon center is described. The key reaction is the cycloaddition of electronically excited carbonyl compounds (aromatic and aliphatic aldehydes, respectively) to oxazoles. To make the products hydrolytically more labile, a methoxy substituent at position

  描述了具有叔（来自相应的甘氨酸等价物）或季 α-碳中心的 α-氨基 β-羟基羧酸衍生物的通用途径。关键反应是电子激发的羰基化合物（分别为芳香醛和脂肪醛）与恶唑的环加成反应。为了使产物水解更不稳定，在 C-5 位引入了甲氧基取代基，导致形成具有原酸酯亚结构的环加合物。光环加成，无论是三线态激发（芳香族）羰基化合物还是单线态激发（脂肪族）羰基化合物，都导致形成具有中等至极高外选择性的内型和外型非对映异构体的混合物。4-未取代的5-甲氧基恶唑1（甘氨酸等价物）以高产率和优异的非对映选择性得到[2+2]-加合物3a-β3f与醛2a-β2f。这些化合物的水解产生具有优选赤型 (S*,S*) 构型的 α-氨基 β-羟基酯 4a??4f...