Diethyl (8R,8aS)-6,7,8,8a-tetrahydro-8-methoxy-1H-pyrano-<3,2-c>-pyridazine-1,2(3H)-dicarboxylate

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二嗪类
• 英文名称: Diethyl (8R,8aS)-6,7,8,8a-tetrahydro-8-methoxy-1H-pyrano-<3,2-c>-pyridazine-1,2(3H)-dicarboxylate
• 英文别名: Diethyl (8R,8aS)-6,7,8,8a-tetrahydro-8-methoxy-1H-pyrano-[3,2-c]-pyridazine-1,2(3H)-dicarboxylate；diethyl (8R,8aS)-8-methoxy-6,7,8,8a-tetrahydro-3H-pyrano[3,2-c]pyridazine-1,2-dicarboxylate
• 化学式: C₁₄H₂₂N₂O₆
• 分子量: 314.338
• InChiKey: AJZPDBCFEVZMNL-PWSUYJOCSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1
• 重原子数：
  22
• 可旋转键数：
  5
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.71
• 拓扑面积：
  77.5
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为产物：
  描述：

  1,5-Anhydro-2-deoxy-4,6-O-(phenylmethylene)-D-arabino-hexopyranoside 在 palladium on activated charcoal pyridine-SO3 complex 、 硫酸 、 氢气 、 sodium hydride 、 二甲基亚砜 、 三乙胺 、 二异丙胺 、 lithium hexamethyldisilazane 作用下， 以 四氢呋喃 、 甲醇 、 乙醇 、 二氯甲烷 、 溶剂黄146 、 苯 为溶剂， 25.0 ℃ 、379.21 kPa 条件下， 反应 534.75h， 生成 Diethyl (8R,8aS)-6,7,8,8a-tetrahydro-8-methoxy-1H-pyrano-<3,2-c>-pyridazine-1,2(3H)-dicarboxylate
  参考文献：
  名称：

  Diastereofacial selectivity of Diels-Alder reactions of carbohydrate-derived dienes and their carbocyclic analogs

  摘要：

  The Diels-Alder reactions of two dienes derived from carbohydrates and their carbocyclic analogs are described. The dienes (2S)-3,4-dihydro-2-methoxy-6-vinyl-2H-pyran (1) and (4R)-3,4-dihydro-4-methoxy-6-vinyl-2H-pyran(2) were synthesized from tri-O-acetyl-D-glucal. Cycloaddition reactions of these dienes, each of which contains a single methoxy group at either the allylic or anomeric position, were carried out with a series of dienophiles including N-phenylmaleimide, dimethyl acetylenedicarboxylate, diethyl azodicarboxylate, and N-phenyl-1,2,4-triazoline-3,5-dione. The incorporation of an amine base in the Diels-Alder reactions was found to be essential for the formation of good yields of unrearranged cycloadducts. Structures of the cycloadducts were assigned using NMR methods and X-ray crystallographic analysis. The diastereofacial selectivities observed for dienes 1 and 2 are compared with those of the analogous carbocyclic dienes 3 and 4, the former of which was synthesized for this study from m-anisic acid. Cycloadditions to both the carbohydrate-derived dienes and their carbocyclic analogs were found to occur with a preference for addition of the dienophile to the face of the diene opposite the methoxyl group in every case. The degree of stereoselectivity was sensitive to a number of factors including the location of the substituents attached to the ring of the semicyclic diene, the presence of oxygen in the ring, and the type of dienophile. The dominant trend for anti addition in the Diels-Alder reactions is discussed in terms of diene conformation and secondary orbital effects in the transition state for cycloaddition.

  DOI：

  10.1021/jo00070a039

文献信息

• Diastereofacial selectivity of Diels-Alder reactions of carbohydrate-derived dienes and their carbocyclic analogs
  作者：Robert M. Giuliano、Alfonzo D. Jordan、A. Diane Gauthier、Karst Hoogsteen

  DOI：10.1021/jo00070a039

  日期：1993.8

  The Diels-Alder reactions of two dienes derived from carbohydrates and their carbocyclic analogs are described. The dienes (2S)-3,4-dihydro-2-methoxy-6-vinyl-2H-pyran (1) and (4R)-3,4-dihydro-4-methoxy-6-vinyl-2H-pyran(2) were synthesized from tri-O-acetyl-D-glucal. Cycloaddition reactions of these dienes, each of which contains a single methoxy group at either the allylic or anomeric position, were carried out with a series of dienophiles including N-phenylmaleimide, dimethyl acetylenedicarboxylate, diethyl azodicarboxylate, and N-phenyl-1,2,4-triazoline-3,5-dione. The incorporation of an amine base in the Diels-Alder reactions was found to be essential for the formation of good yields of unrearranged cycloadducts. Structures of the cycloadducts were assigned using NMR methods and X-ray crystallographic analysis. The diastereofacial selectivities observed for dienes 1 and 2 are compared with those of the analogous carbocyclic dienes 3 and 4, the former of which was synthesized for this study from m-anisic acid. Cycloadditions to both the carbohydrate-derived dienes and their carbocyclic analogs were found to occur with a preference for addition of the dienophile to the face of the diene opposite the methoxyl group in every case. The degree of stereoselectivity was sensitive to a number of factors including the location of the substituents attached to the ring of the semicyclic diene, the presence of oxygen in the ring, and the type of dienophile. The dominant trend for anti addition in the Diels-Alder reactions is discussed in terms of diene conformation and secondary orbital effects in the transition state for cycloaddition.