triethyl (2-iodophenyl)orthoacetate | 887699-73-2

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: triethyl (2-iodophenyl)orthoacetate
• 英文别名: triethyl 2-(2-iodophenyl)orthoacetate；1-Iodo-2-(2,2,2-triethoxyethyl)benzene
• CAS: 887699-73-2
• 化学式: C₁₄H₂₁IO₃
• 分子量: 364.223
• InChiKey: DQGUWLUTMUDSAE-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.6
• 重原子数：
  18
• 可旋转键数：
  8
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.57
• 拓扑面积：
  27.7
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  triethyl (2-iodophenyl)orthoacetate 在 三氟甲磺酸酐 、 二苯基亚砜 、 2,4,5-tri-tert-butylpyrimidine 、 camphor-10-sulfonic acid 、 三氟化硼乙醚 作用下， 以 二氯甲烷 为溶剂， 反应 7.25h， 生成 1-adamantyl 2,3-di-O-benzyl-4,6-O-[1-cyano-2-(2-iodophenyl)]ethylidene-β-D-mannopyranoside
  参考文献：
  名称：

  4,6-O-[1-Cyano-2-(2-iodophenyl)ethylidene] Acetals. Improved Second-Generation Acetals for the Stereoselective Formation of β-d-Mannopyranosides and Regioselective Reductive Radical Fragmentation to β-d-Rhamnopyranosides. Scope and Limitations

  摘要：

  The [1-cyano-2-(2-iodophenyl)]ethylidene group is introduced as an acetal-protecting group for carbohydrate thioglycoside donors. The group is easily introduced under mild conditions, over short reaction times, and in the presence of a wide variety of other protecting groups by the reaction of the 4,6-diol with triethyl (2-iodophenyl)orthoacetate and camphorsulfonic acid, followed by trimethylsilyl cyanide and boron trifluoride etherate. The new protecting group conveys strong beta-selectivity with thiomannoside donors and undergoes a tin-mediated radical fragmentation to provide high yields of the synthetically challenging beta-rhamnopyranosides. The method is also applicable to the glucopyranosides when high beta-selectivity is observed in the coupling reaction and alpha-quinovosides are formed selectively in the radical fragmentation step. In the galactopyranoside series, beta-glycosides are formed selectively on coupling to donors protected by the new system, but the radical fragmentation is unselective and gives mixtures of the 4- and 6-deoxy products. Variable-temperature NMR studies for the glycosylation step, which helped define an optimal protocol, are described.

  DOI：

  10.1021/jo0526688
• 作为产物：
  描述：

  2-碘苯基乙腈 在 盐酸 作用下， 反应 48.0h， 生成 triethyl (2-iodophenyl)orthoacetate
  参考文献：
  名称：

  4,6-O-[1-Cyano-2-(2-iodophenyl)ethylidene] Acetals. Improved Second-Generation Acetals for the Stereoselective Formation of β-d-Mannopyranosides and Regioselective Reductive Radical Fragmentation to β-d-Rhamnopyranosides. Scope and Limitations

  摘要：

  The [1-cyano-2-(2-iodophenyl)]ethylidene group is introduced as an acetal-protecting group for carbohydrate thioglycoside donors. The group is easily introduced under mild conditions, over short reaction times, and in the presence of a wide variety of other protecting groups by the reaction of the 4,6-diol with triethyl (2-iodophenyl)orthoacetate and camphorsulfonic acid, followed by trimethylsilyl cyanide and boron trifluoride etherate. The new protecting group conveys strong beta-selectivity with thiomannoside donors and undergoes a tin-mediated radical fragmentation to provide high yields of the synthetically challenging beta-rhamnopyranosides. The method is also applicable to the glucopyranosides when high beta-selectivity is observed in the coupling reaction and alpha-quinovosides are formed selectively in the radical fragmentation step. In the galactopyranoside series, beta-glycosides are formed selectively on coupling to donors protected by the new system, but the radical fragmentation is unselective and gives mixtures of the 4- and 6-deoxy products. Variable-temperature NMR studies for the glycosylation step, which helped define an optimal protocol, are described.

  DOI：

  10.1021/jo0526688

文献信息

• Stereocontrolled Synthesis of the <scp>d</scp>- and <scp>l</scp>-<i>glycero</i>-β-<scp>d</scp>-<i>manno</i>-Heptopyranosides and Their 6-Deoxy Analogues. Synthesis of Methyl α-<scp>l</scp>-<i>Rhamno</i>-pyranosyl-(1→3)-<scp>d</scp>-<i>glycero</i>-β-<scp>d</scp>-<i>manno</i>-heptopyranosyl- (1→3)-6-deoxy-<i>glycero</i>-β-<scp>d</scp>-<i>manno</i>-heptopyranosyl-(1→4)-α-<scp>l</scp>- <i>rhamno</i>-pyranoside, a Tetrasaccharide Subunit of the Lipopolysaccharide from <i>Plesimonas shigelloides</i>
  作者：David Crich、Abhisek Banerjee

  DOI：10.1021/ja061594u

  日期：2006.6.1

  The synthesis of D-and L-glycero-alpha-manno-thioheptopyranosides, protected with 4,6-O-alkylidenetype acetals is described. In glycosylations carried out with preactivation with the 1-benzenesulfinylpiperidine/trifluoromethanesulfonic anhydride couple, both the D-and L-glycero series exhibit excellent, beta-selectivity with a range of glycosyl acceptors. In contrast, a 4,7-O-alkylidene acetal was found not to afford, beta-selectivity. With a 4,6-O-[1-cyano-2-(2-iodophenyl) ethylidene] acetal protected thioglycoside, excellent, beta-selectivity was obtained in glycosylation reactions, and subsequent treatment with tributyltin hydride and azoisobutyronitrile brought about clean fragmentation to the 6-deoxy-glycero-beta-D-manno-heptopyranosides. This chemistry was applied to the stereocontrolled synthesis of methyl alpha-L-rhamno-pyranosyl-(1 -> 3)-D-glycero-beta- D-manno-heptopyranosyl-(1 -> 3)-6-deoxy-glycero-beta-D-manno-heptopyranosyl-(1 -> 4)-alpha-L-rhamno-pyranoside, a component of the lipopolysaccharide from Plesimonas shigelloides.
• Direct Stereocontrolled Synthesis of 3-Amino-3-deoxy-β-Mannopyranosides:  Importance of the Nitrogen Protecting Group on Stereoselectivity
  作者：David Crich、Huadong Xu

  DOI：10.1021/jo070473p

  日期：2007.7.1

  The highly stereocontrolled synthesis of the 3-amino-3-deoxy-beta-mannopyranosides is achieved by means of thioglycoside donors protected with a 4,6-O-benzylidene or alkylidene acetal and a benzylidene imine group. Among the various nitrogen protecting groups investigated only the Schiff's base was found to give high beta-selectivity. N-Phthalimido and N-acetamido protected donors were found to be highly alpha-selective, whereas 3-azido-3-deoxy glycosyl donors gave intermediate selectivity. The reasons for the protecting group dependency are discussed in terms of the change in the O2-C2-C3-N3 torsional interaction on conversion of the covalent glycosyl triflates to the transient oxacarbenium ions.
• Synthesis of a β-(1→3)-<scp>d</scp>-Rhamnotetraose by a One-Pot, Multiple Radical Fragmentation
  作者：David Crich、Albert A. Bowers

  DOI：10.1021/ol061706m

  日期：2006.9

  A naturally occurring beta-(1 -> 3)-D-rhamnotetraose has been constructed under conditions of sequential beta-selective mannosylation controlled by the 4,6-O-[1-cyano-2-(2-iodophenyl)-ethylidene] protecting group. The route is concise, proceeding through a late-stage radical deoxygenation that successfully uncovers all four deoxy subunits at once.