Pentenyl 2,4-di-O-benzyl-α-D-mannopyranoside | 143706-43-8

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: Pentenyl 2,4-di-O-benzyl-α-D-mannopyranoside
• 英文别名: (2R,3S,4S,5S,6S)-2-(hydroxymethyl)-6-pent-4-enoxy-3,5-bis(phenylmethoxy)oxan-4-ol
• CAS: 143706-43-8
• 化学式: C₂₅H₃₂O₆
• 分子量: 428.525
• InChiKey: QBEZHVMPMUXYAM-KJWQXZETSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.9
• 重原子数：
  31
• 可旋转键数：
  12
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.44
• 拓扑面积：
  77.4
• 氢给体数：
  2
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  Pentenyl 2,4-di-O-benzyl-α-D-mannopyranoside 在 四乙基溴化铵 、 溴 作用下， 以 二氯甲烷 为溶剂， 生成 (2S,3S,4S,5S,6R)-2-(4,5-dibromopentoxy)-6-(hydroxymethyl)-3,5-bis(phenylmethoxy)oxan-4-ol
  参考文献：
  名称：

  n-Pentenyl Mannoside Precursors for Synthesis of the Nonamannan Component of High Mannose Glycoproteins

  摘要：

  The high-mannose oligosaccharide 1 is present on the conserved V3 loop of the viral coat of HIV1 known as GP-120. The mannan portion of this molecule has been prepared by utilization of halogen-promoted n-pentenyl glycoside (NPG) coupling. Two advantageous properties of NPG's facilitated construction of 1, one being the ability to activate the donor, even when C2 esterified (i.e., ''disarmed''), with NIS/Et(3)SiOTf, under which all reactions are complete within the time required to take a TLC sample. The second advantage was the ''side-tracking'' strategy which allowed the pentenyl group of a glycosyl acceptor to be rendered temporarily inactive by conversion to the dibromide. After coupling, the ''side-tracked'' NPG could be reactivated by reductive elimination to serve as the glycosyl donor in a subsequent step. With the appropriately protected monosaccharide precursors in hand, the nonamannan could be assembled by a virtually iterative protocol involving deprotection-coupling- deprotection-coupling...etc. as the only synthetic manipulations.

  DOI：

  10.1021/jo00095a020
• 作为产物：
  描述：

  1,3,6-tri-O-acetyl-2,4-di-O-benzyl-α-D-mannopyranose 在 sodium methylate 、 四氯化锡 作用下， 以 甲醇 、 二氯甲烷 为溶剂， 反应 2.0h， 生成 Pentenyl 2,4-di-O-benzyl-α-D-mannopyranoside
  参考文献：
  名称：

  n-Pentenyl Mannoside Precursors for Synthesis of the Nonamannan Component of High Mannose Glycoproteins

  摘要：

  The high-mannose oligosaccharide 1 is present on the conserved V3 loop of the viral coat of HIV1 known as GP-120. The mannan portion of this molecule has been prepared by utilization of halogen-promoted n-pentenyl glycoside (NPG) coupling. Two advantageous properties of NPG's facilitated construction of 1, one being the ability to activate the donor, even when C2 esterified (i.e., ''disarmed''), with NIS/Et(3)SiOTf, under which all reactions are complete within the time required to take a TLC sample. The second advantage was the ''side-tracking'' strategy which allowed the pentenyl group of a glycosyl acceptor to be rendered temporarily inactive by conversion to the dibromide. After coupling, the ''side-tracked'' NPG could be reactivated by reductive elimination to serve as the glycosyl donor in a subsequent step. With the appropriately protected monosaccharide precursors in hand, the nonamannan could be assembled by a virtually iterative protocol involving deprotection-coupling- deprotection-coupling...etc. as the only synthetic manipulations.

  DOI：

  10.1021/jo00095a020

文献信息

• Regioselective Strategies Mediated by Lanthanide Triflates for Efficient Assembly of Oligomannans
  作者：K. N. Jayaprakash、Siddhartha Ray Chaudhuri、Changalvala V. S. R. Murty、Bert Fraser-Reid

  DOI：10.1021/jo070018t

  日期：2007.7.1

  trichloroacetimidates as well as ethyl and phenyl thioglycosides can be achieved. Appropriate NPOEs are also able to provide 2,6 and 3,6 diol acceptors via rearrangement or glycoside formation, and these can be used for one-pot, sequential glycosidations based on orthogonal donors, and in situ double differential glycosidations. Thus NPOEs activated by iodonium ion, specifically generated from ytterbium

  现成的甘露糖基正戊烯基原酸酯（NPOE）本身可作为供体，也可作为其他糖基供体（如n-戊烯基糖苷（NPG），硫代糖苷和三氯乙亚氨酸盐。这些不同的供体被不同的试剂激活，因此适合多种用途。flat和flat三氟甲磺酸盐对这些供体的反应非常不同，其结果是可以实现NPOE，NPG，三氯乙亚氨酸盐以及乙基和苯基硫代糖苷之间的化学选择性区分。适当的NPOE也能够通过重排或糖苷形成提供2,6和3,6二醇受体，并且它们可用于基于正交供体的一锅顺序糖苷化和原位双差分糖苷化。因此，由碘鎓离子激活的NPOE，特别是由三氟甲磺酸/ N-碘代琥珀酰亚胺可用于快速单糖苷化二醇，具有出色的区域选择性，有时还具有化学选择性。残留的NPOE被转化为对反应条件具有抵抗力的脱甲NPG，因此不会对单糖苷化产物的游离OH构成威胁。然后可以通过直接添加三氯乙酰亚胺酸酯或乙基硫代糖苷来实现后者的进一步糖苷化。该基本策略已被用于制备支链五
• A study of n-pentenylorthoesters having manno, gluco and galacto configurations in regioselective glycosylations
  作者：K.N. Jayaprakash、Bert Fraser-Reid

  DOI：10.1016/j.carres.2006.09.022

  日期：2007.2

  Kochetkov's extensive investigations of glycosyl orthoester and their analogs as glycosyl donors revealed that the alkyl derivatives were plagued by competition between the departing alcohol and the incoming acceptor. n-Pentenyl orthoesters (NPOEs) obviate competition by sequestering the departing pentenyl alcohol as a 2-halomethyl tetrahydrofuran. Exquisitely regioselective glycosidations of diol acceptors can be carried out with NPOEs triggered specifically with Yb(OTf)(3)/NIS. However with Sc(OTf)(3), double glycosidation is the major reaction. manno, gluco and galacto NPOEs have been investigated. The latter two, which require a different experimental procedure for the manno counterpart, also give an excellent regioselectivity with Yb(OTf)(3), but the yields are much lower than with manno. (c) 2006 Elsevier Ltd. All rights reserved.