phenylthio 2,3-di-O-benzyl-4-O-(p-methoxybenzyl)-6-(tert-butyldimethylsiloxy)-α-D-mannopyranoside | 1421832-74-7

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: phenylthio 2,3-di-O-benzyl-4-O-(p-methoxybenzyl)-6-(tert-butyldimethylsiloxy)-α-D-mannopyranoside
• 英文别名: Bn(-2)[Bn(-3)][Mob(-4)][TBDMS(-6)]Man(a)-SPh；tert-butyl-[[(2R,3R,4S,5S,6R)-3-[(4-methoxyphenyl)methoxy]-4,5-bis(phenylmethoxy)-6-phenylsulfanyloxan-2-yl]methoxy]-dimethylsilane
• CAS: 1421832-74-7
• 化学式: C₄₀H₅₀O₆SSi
• 分子量: 686.985
• InChiKey: NWGNPNNHLVVICA-WEMFOFRKSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  9.29
• 重原子数：
  48
• 可旋转键数：
  16
• 环数：
  5.0
• sp3杂化的碳原子比例：
  0.4
• 拓扑面积：
  80.7
• 氢给体数：
  0
• 氢受体数：
  7

反应信息

• 作为反应物：
  描述：

  phenylthio 2,3-di-O-benzyl-4-O-(p-methoxybenzyl)-6-(tert-butyldimethylsiloxy)-α-D-mannopyranoside 在 Stryker's reagent 、 二苯基亚砜 、 四丁基氟化铵 、 水 、 戴斯-马丁氧化剂 、 2,3-二氯-5,6-二氰基-1,4-苯醌 、 2,4,6-三叔丁基嘧啶 作用下， 以 四氢呋喃 、 甲醇 、 二氯甲烷 、 二氯甲烷-D2 、 苯 为溶剂， 反应 87.17h， 生成 (2R,3S,4S,4aR,6S,8aR)-3,4-bis(benzyloxy)-6-phenyloctahydropyrano[3,2-b]pyran-2-yl trifluoromethanesulfonate
  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
• 作为产物：
  描述：

  S-phenyl 2,3-di-O-benzyl-α-D-thiomannopyranoside 在 咪唑 、 sodium hydride 作用下， 以 N,N-二甲基甲酰胺 、 mineral oil 为溶剂， 反应 4.5h， 生成 phenylthio 2,3-di-O-benzyl-4-O-(p-methoxybenzyl)-6-(tert-butyldimethylsiloxy)-α-D-mannopyranoside
  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.