4,5-dibromopentanyl 3,4,6-tri-O-benzyl-α-D-mannopyranoside | 143706-46-1

• 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: 4,5-dibromopentanyl 3,4,6-tri-O-benzyl-α-D-mannopyranoside
• 英文别名: Dibromopentanyl 3,4,6-tri-O-benzyl-α-D-mannopyranoside
• CAS: 143706-46-1
• 化学式: C₃₂H₃₈Br₂O₆
• 分子量: 678.458
• InChiKey: OLMOQIHRZDPONV-NKZUHYLHSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  6.42
• 重原子数：
  40.0
• 可旋转键数：
  16.0
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.44
• 拓扑面积：
  66.38
• 氢给体数：
  1.0
• 氢受体数：
  6.0

反应信息

• 作为反应物：
  描述：

  4,5-dibromopentanyl 3,4,6-tri-O-benzyl-α-D-mannopyranoside 在 N-碘代丁二酰亚胺 、 氨 、 三乙基硅基三氟甲磺酸酯 作用下， 以 甲醇 、 二氯甲烷 、 丙酮 为溶剂， 反应 96.05h， 生成 Dibromopentanyl O-(3,4,6-tri-O-benzyl-α-D-mannopyranosyl)-(1->2)-3,4,6-tri-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
• 作为产物：
  描述：

  4-penten-1-yl 2-O-acetyl-2,3,6-tri-O-benzyl-α-D-glucopyranoside 在 四乙基溴化铵 、 溴 、 potassium carbonate 作用下， 以 甲醇 、 二氯甲烷 为溶剂， 反应 1.5h， 生成 4,5-dibromopentanyl 3,4,6-tri-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

• n-Pentenyl furanosides: synthesis and glycosidation reactions of some galacto derivatives
  作者：Ashok Arasappan、Bert Fraser-Reid

  DOI：10.1016/0040-4039(95)01718-w

  日期：1995.10

  Synthetic routes to n-pentenyl galactofuranosides and glycosidation reactions of some derived donors with alcohol and saccharide acceptors using NIS/TESOTf as the promoter are described.

  描述了使用NIS / TESOTf作为促进剂的合成正戊烯基半乳糖呋喃糖苷的合成路线以及一些衍生的供体与醇和糖受体的糖基化反应。
• Studies Related to Synthesis of Glycophosphatidylinositol Membrane-Bound Protein Anchors. 5. n-Pentenyl Ortho Esters for Mannan Components
  作者：Carmichael Roberts、Robert Madsen、Bert Fraser-Reid

  DOI：10.1021/ja00110a010

  日期：1995.2

  Procedures for rapid assembly of multigram amounts of mannan components have been examined. Although these studies are reported in the context of the mannan moiety of the glycan anchors of membrane-bound glycoproteins, the procedures should be applicable to the wider family of mannose-containing glycoproteins. Readily prepared n-pentenyl ortho esters of mannose are shown to be versatile substrates that can serve as glycosyl donors in their own right or be used to furnish mannosyl bromides or n-pentenyl alpha-D-mannosides. Thus three glycosyl donors of different reactivities and stabilities are obtainable from the same precursor, all three being activated under mild conditions. Two approaches are described. in the first, a portion of the starting n-pentenyl ortho ester is converted into an n-pentenyl glycoside (NPG) by acid-catalyzed rearrangement, while another portion is titrated with bromine to give a glycosyl bromide. These are coupled under Koenigs-Knorr conditions to give an n-pentenyl disaccharide which is then processed to become a glycosyl acceptor. A third portion of the ortho ester, after suitable protecting group adjustments, is also titrated with bromine and coupled to the disaccharide acceptor to give the desired trimannan. The instability of glycosyl bromides detracts from this route, and so a second approach which avoids their use completely was pursued in which NPG obtained from the acid-catalyzed rearrangement was converted into a vicinal dibromide. The latter is then able to serve as a glycosyl acceptor for coupling to a donor obtainable by reaction of the n-pentenyl ortho ester with halonium ion. The dibromopentanyl disaccharide produced then becomes an acceptor for a donor derived from n-pentenyl mannoside. The second approach uses no unstable reactants, is therefore experimentally less demanding, and can be operated conveniently on a large scale.