1-adamantanyl 4,8-anhydro-2,3-di-O-benzyl-6,7-dideoxy-8S-phenyl-α-D-manno-octopyranoside | 1421832-82-7

• 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: 1-adamantanyl 4,8-anhydro-2,3-di-O-benzyl-6,7-dideoxy-8S-phenyl-α-D-manno-octopyranoside
• 英文别名: (2R,3S,4S,4aR,6S,8aR)-2-(1-adamantyloxy)-6-phenyl-3,4-bis(phenylmethoxy)-2,3,4,4a,6,7,8,8a-octahydropyrano[3,2-b]pyran
• CAS: 1421832-82-7
• 化学式: C₃₈H₄₄O₅
• 分子量: 580.764
• InChiKey: SSYXGJXXCQXWIA-UQNOFSTISA-N

计算性质

• 辛醇/水分配系数(LogP)：
  7.4
• 重原子数：
  43
• 可旋转键数：
  9
• 环数：
  9.0
• sp3杂化的碳原子比例：
  0.53
• 拓扑面积：
  46.2
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为产物：
  描述：

  S-phenyl 2,3-di-O-benzyl-α-D-thiomannopyranoside 在 吡啶 、 甲醇 、 4-二甲氨基吡啶 、 Stryker's reagent 、 1-(苯基亚硫酰基)哌啶 、 水 、 sodium methylate 、 戴斯-马丁氧化剂 、 三氟乙酸 、 三氟乙酸酐 、 2,4,6-三叔丁基嘧啶 作用下， 以 四氢呋喃 、 甲醇 、 二氯甲烷 、 苯 为溶剂， 反应 267.5h， 生成 1-adamantanyl 4,8-anhydro-2,3-di-O-benzyl-6,7-dideoxy-8S-phenyl-α-D-manno-octopyranoside 、 1-adamantanyl 4,8-anhydro-2,3-di-O-benzyl-6,7-dideoxy-8S-phenyl-β-D-manno-octopyranoside
  参考文献：
  名称：

  Influence of O6 in Mannosylations Using Benzylidene Protected Donors: Stereoelectronic or Conformational Effects?

  摘要：

  The stereoselective synthesis of beta-mannosides and the underlying reaction mechanism have been thoroughly studied, and especially the benzylidene-protected mannosides have gained a lot of attention since the corresponding mannosyl triflates often give excellent selectivity. The hypothesis for the enhanced stereoselectivity has been that the benzylidene locks the molecule in a less reactive conformation with the O6 trans to the ring oxygen (O5), which would stabilize the formed alpha-triflate and subsequent give beta-selectivity. In this work, the hypothesis is challenged by using the carbon analogue (C7) of the benzylidene-protected mannosyl donor, which is investigated in terms of diastereoselectivity and reactivity and by low-temperature NMR In terms of diastereoselectivity, the C-7-analogue behaves similarly to the benzylidene-protected donor, but its low-temperature NMR reveals the formation of several reactive intermediate. One of the intermediates was found to be the beta-oxosulfonium ion. The reactivity of the donor was found to be in between that of the "torsional" disarmed and an armed donor.

  DOI：

  10.1021/jo302455d

文献信息

• Influence of O6 in Mannosylations Using Benzylidene Protected Donors: Stereoelectronic or Conformational Effects?
  作者：Tobias Gylling Frihed、Marthe T. C. Walvoort、Jeroen D. C. Codée、Gijs A. van der Marel、Mikael Bols、Christian Marcus Pedersen

  DOI：10.1021/jo302455d

  日期：2013.3.15

  The stereoselective synthesis of beta-mannosides and the underlying reaction mechanism have been thoroughly studied, and especially the benzylidene-protected mannosides have gained a lot of attention since the corresponding mannosyl triflates often give excellent selectivity. The hypothesis for the enhanced stereoselectivity has been that the benzylidene locks the molecule in a less reactive conformation with the O6 trans to the ring oxygen (O5), which would stabilize the formed alpha-triflate and subsequent give beta-selectivity. In this work, the hypothesis is challenged by using the carbon analogue (C7) of the benzylidene-protected mannosyl donor, which is investigated in terms of diastereoselectivity and reactivity and by low-temperature NMR In terms of diastereoselectivity, the C-7-analogue behaves similarly to the benzylidene-protected donor, but its low-temperature NMR reveals the formation of several reactive intermediate. One of the intermediates was found to be the beta-oxosulfonium ion. The reactivity of the donor was found to be in between that of the "torsional" disarmed and an armed donor.