phenylthio 2,3-di-O-benzyl-6-(tert-butyldimethylsiloxy)-α-D-mannopyranoside | 1421832-73-6

• 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-6-(tert-butyldimethylsiloxy)-α-D-mannopyranoside
• 英文别名: phenyl 6-OTBS-2,3-di-OBn-1-thio-a-D-mannopyranoside
• CAS: 1421832-73-6
• 化学式: C₃₂H₄₂O₅SSi
• 分子量: 566.834
• InChiKey: DILBOIIWESQARK-ZOROSQJXSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  7.06
• 重原子数：
  39.0
• 可旋转键数：
  11.0
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.44
• 拓扑面积：
  57.15
• 氢给体数：
  1.0
• 氢受体数：
  6.0

反应信息

• 作为反应物：
  描述：

  phenylthio 2,3-di-O-benzyl-6-(tert-butyldimethylsiloxy)-α-D-mannopyranoside 在 Stryker's reagent 、 1-(苯基亚硫酰基)哌啶 、 四丁基氟化铵 、 水 、 sodium hydride 、 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 、 N,N-二甲基甲酰胺 、 mineral oil 、 苯 为溶剂， 反应 90.0h， 生成 methyl (4,8-anhydro-2,3-di-O-benzyl-6,7-dideoxy-8S-C-phenyl-β-D-manno-octopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-α-D-glucopyranoside
  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：

  phenyl 2,3-di-O-benzyl-4,6-O-benzylidene-1-thio-α-D-mannopyranoside 在 咪唑 、 对甲苯磺酸 作用下， 以 甲醇 、 二氯甲烷 、 N,N-二甲基甲酰胺 为溶剂， 反应 21.0h， 生成 phenylthio 2,3-di-O-benzyl-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

• Organotin-catalyzed regioselective benzylation of carbohydrate trans-diols
  作者：Hengfu Xu、Ying Zhang、Hai Dong、Yuchao Lu、Yuxin Pei、Zhichao Pei

  DOI：10.1016/j.tetlet.2017.08.043

  日期：2017.10

  approach to regioselective benzylation of carbohydrate trans-diols was developed, where 0.1 equiv. of Bu2SnCl2 and 0.1 equiv. of TBABr were used as the catalysts and 2.0 equiv. of BnCl was used as the benzylation reagent. In most cases, similar or better benzylation regioselectivities and isolated yields were obtained by using catalytic amounts of Bu2SnCl2, rather than stoichiometric amounts of organotin

  开发了一种方便的方法，用于碳水化合物反式二醇的区域选择性苄化，其中0.1当量。的Bu 2 SnCl 2和0.1当量 使用TBABr 2的催化剂作为催化剂，当量为2.0当量。将BnCl 2用作苄基化试剂。在大多数情况下，通过使用催化量的Bu 2 SnCl 2而不是所需化学计量的有机锡试剂，可获得相似或更好的苄基化区域选择性和分离的产率。