(7-acetyloxy-6-methoxy-4,4a,6,7,8,8a-hexahydropyrano[3,2-d][1,3]dioxin-8-yl) acetate | 50256-58-1

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡喃二恶英
• 英文名称: (7-acetyloxy-6-methoxy-4,4a,6,7,8,8a-hexahydropyrano[3,2-d][1,3]dioxin-8-yl) acetate
• 英文别名: 2,3-O-diacetyl-(4,6-O-methylidene)methyl-α-D-mannopyranoside；methyl 2,3-O-diacetyl-4,6-O-methylidene-α,D-mannopyranoside；Methyl-2.3-di-O-acetyl-4.6-O-methylen-α-D-mannopyranosid
• CAS: 50256-58-1
• 化学式: C₁₂H₁₈O₈
• 分子量: 290.27
• InChiKey: UXVNCXFWXYDQRO-GCHJQGSQSA-N

物化性质

• 沸点：
  367.3±42.0 °C(Predicted)
• 密度：
  1.29±0.1 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  -0.41
• 重原子数：
  20.0
• 可旋转键数：
  3.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  89.52
• 氢给体数：
  0.0
• 氢受体数：
  8.0

反应信息

• 作为产物：
  描述：

  (4,6-O-methylidene)methyl-α-D-mannopyranoside 、 乙酸酐 在 4-二甲氨基吡啶 作用下， 以 二氯甲烷 为溶剂， 反应 24.0h， 以17%的产率得到(7-acetyloxy-6-methoxy-4,4a,6,7,8,8a-hexahydropyrano[3,2-d][1,3]dioxin-8-yl) acetate
  参考文献：
  名称：

  用寡肽催化剂对吡喃糖苷进行位点选择性酰化

  摘要：

  在此，我们报道了部分保护的单糖的寡肽催化的位点选择性酰化。我们确定了催化剂，其反转的网站选择性相比ñ甲基咪唑，这是用来确定内在反应，为4,6- Ø重保护的吡喃葡萄糖苷（反式-diols）以及4,6- Ø -protected mannopyranosides（顺-二醇）。在温和的反应条件下，该反应产生高达81％的固有不利的2- O-乙酰化产物，选择性高达15：1。我们还确定了保护基对反应的影响，并证明我们的方案适用于具有多个连续保护步骤的一锅法反应。

  DOI：

  10.1021/acs.joc.0c02772

文献信息

• In Situ Switching of Site-Selectivity with Light in the Acetylation of Sugars with Azopeptide Catalysts
  作者：Dominik Niedek、Frederik R. Erb、Christopher Topp、Alexander Seitz、Raffael C. Wende、André K. Eckhardt、Jonas Kind、Dominik Herold、Christina M. Thiele、Peter R. Schreiner

  DOI：10.1021/acs.joc.9b01913

  日期：2020.2.21

  We present a novel concept for the in situ control of site-selectivity of catalytic acetylations of partially protected sugars using light as external stimulus and oligopeptide catalysts equipped with an azobenzene moiety. The isomerizable azobenzene-peptide backbone defines the size and shape of the catalytic pocket, while the π-methyl-l-histidine (Pmh) moiety transfers the electrophile. Photoisomerization of the E- to the Z-azobenzene catalyst (monitored via NMR) with an LED (λ = 365 nm) drastically changes the chemical environment around the catalytically active Pmh moiety, so that the light-induced change in the catalyst shape alters site-selectivity. As a proof of principle, we employed (4,6-O-benzylidene)methyl-α-d-pyranosides, which provide a change in regioselectivity from 2:1 (E) to 1:5 (Z) for the monoacetylated products at room temperature. The validity of this new catalyst-design concept is further demonstrated with the regioselective acetylation of the natural product quercetin. In situ irradiation NMR spectroscopy was used to quantify photostationary states under continuous irradiation with UV light.