methyl (6R)-C-ethyl-α-D-glucopyranoside | 161147-34-8

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: methyl (6R)-C-ethyl-α-D-glucopyranoside
• 英文别名: (2R,3S,4S,5R,6S)-2-[(1S)-1-hydroxypropyl]-6-methoxyoxane-3,4,5-triol
• CAS: 161147-34-8
• 化学式: C₉H₁₈O₆
• 分子量: 222.238
• InChiKey: COGJTEJUOYYBDL-LLVDSZRASA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -1.1
• 重原子数：
  15
• 可旋转键数：
  3
• 环数：
  1.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  99.4
• 氢给体数：
  4
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  苯甲醛二甲缩醛 、 methyl (6R)-C-ethyl-α-D-glucopyranoside 在 对甲苯磺酸 作用下， 以 N,N-二甲基甲酰胺 为溶剂， 反应 48.0h， 以79%的产率得到Methyl 4,6-O-benzylidene-7,8-dideoxy-L-glycero-α-D-gluco-octopyranoside
  参考文献：
  名称：

  Chain-Extension of Carbohydrates. 5. Synthesis of the C-Glycosyl Amino Acid Moiety of Miharamycins Involving Stereocontrolled Ethynylation of Methyl 2,3,4-Tri-O-benzyl-.alpha.-D-gluco-hexodialdo-1,5-pyranoside

  摘要：

  A multistep synthesis of the C-glycosyl amino acid moiety of miharamycins from methyl 2,3,4-tri-O-benzyl-alpha-D-gluco-hexodialdo-1,5-pyranoside (1) is described, The ethynyl group was employed as a synthetic equivalent of the carboxylic acid function, In the key step, highly diastereoselective ethynylation of compound 1 with the Grignard reagent of (trimethylsilyl)acetylene in the presence of magnesium bromide followed by desilylation afforded acetylenic alcohols 4 and 5 (19:1). The L-glycero configuration at C(6) of the major isomer 4 was unambiguously proven by H-1 NMR of the 4,6-benzylidene derivative 9. The amino function was introduced at C(6) by reaction of 4 with zinc azide in the presence of triphenylphosphine and diisopropyl azodicarboxylate. Transformation of the resulting methyl 6-azido-2,3,4-tri-O-benzyl-6,7,8-trideoxy side (10) into methyl 6-(N-acetylamino)-2,3,4-tri-O-benzyl-6-deoxy-D-glycero-alpha-D-gluco-heptopyranosiduronic acid (17) was achieved by two different sequences of reactions: (1) oxidative cleavage of the triple bond, benzylation, reduction of the azido group, and N-acetylation or (2) reduction of the azido group, N-acetylation, oxidative cleavage of the triple bond, and treatment with phenyldiazomethane. The overall yield of the two sequences was different (41% versus 50%), showing the second method to be superior. Final debenzylation afforded methyl 6-(N-acetylamino)6-deoxy-L-glycero-alpha-D-gluco-heptopyranisoduronic acid (18). To prepare the epimeric amino acid derivative 28, the configuration at C(6) of 4 was inverted by a Mitsunobu reaction. The same sequence of reactions was applied to the so-obtained D-glycero isomer 5 and methyl 6-(N-acetyl-amino)-6-deoxy-L-glycero-alpha-D-gluco-heptopyranosiduronic acid (28) was obtained. In this case almost identical overall yields were obtained for the two different transformations of the azidoalkyne 20 to compound 28 (62% versus 63%).

  DOI：

  10.1021/jo00108a030
• 作为产物：
  描述：

  methyl 6-aldehydo-2,3,4-tri-O-benzyl-α-D-glucopyranoside 在 palladium on activated charcoal 氢气 作用下， 以 甲醇 、 乙醚 为溶剂， 生成 methyl (6R)-C-ethyl-α-D-glucopyranoside
  参考文献：
  名称：

  The syntheses of 6-C-alkyl derivatives of methyl α-isomaltoside for a study of the mechanism of hydrolysis by amyloglucosidase

  摘要：

  为了研究引入不同大小烷基基团对酶类淀粉酶（EC 3.2.1.3，通常称为葡萄糖淀粉酶）对α-糖苷键水解速率的影响，合成了甲基α-异麦芽糖苷（1）的异构体（6aR）-和（6aS）-C-烷基（甲基、乙基和异丙基）衍生物。之前已确定，甲基（6aR）-C-甲基α-异麦芽糖苷的水解速率约比甲基α-异麦芽糖苷快大约2倍，比其S-异构体快大约8倍。最近还发表了乙基和异丙基类似物的水解动力学。正如从分子模型计算所预期的那样，所有的R-异构体都是良好的底物。提出了基于传统机械理论的催化理论，包括通过氢键将4a-羟基与色氨酸和精氨酸单元连接起来，以促进激活复合物向产物的分解。建议初始形成的复合物向过渡态的激活是通过由受扰动的水分子在多胶性底物和结合位点表面的脱水和分子间氢键的建立释放的能量来辅助的，即微热力学。周围环绕结合位点的芳香氨基酸壳层阻碍了热量向大量溶液的传播。这种屏蔽层已知位于凝集素和特异性碳水化合物抗体的结合位点周围，并被认为是必要的，以防止破坏分子间氢键，这对于复合物的稳定性至关重要。这些特征与结合位点内反应分子的精致立体电子排布一起，为在常温和接近中性pH下的催化提供了合理解释。合成涉及将烷基格氏试剂加到甲基6-醛基-α-D-葡萄糖吡喃糖。加成有利于S-异构体的形成，超过90%。通过使用传统方法在手性中心进行异构化，得到了活性R-异构体的有用量。在溴离子催化条件下对所得醇进行糖基化，提供了甲基（6aS）-和（6aR）-C-烷基-七O-苄基-α-异麦芽糖苷。对苄基团的催化氢解得到了期望的二糖。通过1H核磁共振研究，确定了绝对构型并提供了构象偏好的证据。关键词：淀粉酶（AMG），外部异构效应，6-C-烷基-α-D-葡萄糖吡喃糖和异麦芽糖苷，酶催化机制。

  DOI：

  10.1139/v01-005