ethyl 3-O-acetyl-2-O-benzyl-4,6-O-benzylidene-β-D-glucopyranosyl-(1→3)-2-O-benzyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside | 1541179-53-6

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: ethyl 3-O-acetyl-2-O-benzyl-4,6-O-benzylidene-β-D-glucopyranosyl-(1→3)-2-O-benzyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside
• CAS: 1541179-53-6
• 化学式: C₄₄H₄₈O₁₁S
• 分子量: 784.925
• InChiKey: ATMGOZMREHXGBE-WPNDJSMUSA-N

物化性质

• 沸点：
  846.1±65.0 °C(predicted)
• 密度：
  1.32±0.1 g/cm3(Temp: 20 °C; Press: 760 Torr)(predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  6.91
• 重原子数：
  56.0
• 可旋转键数：
  13.0
• 环数：
  8.0
• sp3杂化的碳原子比例：
  0.43
• 拓扑面积：
  109.37
• 氢给体数：
  0.0
• 氢受体数：
  12.0

反应信息

• 作为产物：
  描述：

  3-O-acetyl-2-O-benzyl-4,6-O-benzylidene-D-glucopyranose 在 ammonium cerium (IV) nitrate 、 三氟甲烷磺酸甲酯 作用下， 以 二氯甲烷 、 水 、 乙腈 为溶剂， 反应 0.58h， 生成 ethyl 3-O-acetyl-2-O-benzyl-4,6-O-benzylidene-α-D-glucopyranosyl-(1→3)-2-O-benzyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside 、 ethyl 3-O-acetyl-2-O-benzyl-4,6-O-benzylidene-β-D-glucopyranosyl-(1→3)-2-O-benzyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside
  参考文献：
  名称：

  Is an acyl group at O-3 in glucosyl donors able to control α-stereoselectivity of glycosylation? The role of conformational mobility and the protecting group at O-6

  摘要：

  The stereodirecting effect of a 3-O-acetyl protecting group, which is potentially capable of the remote anchimeric participation, and other protecting groups in 2-O-benzyl glucosyl donors with flexible and rigid conformations has been investigated. To this aim, an array of N-phenyltrifluoroacetimidoyl and sulfoxide donors bearing either 3-O-acetyl or 3-O-benzyl groups in combination with 4,6-di-O-benzyl, 6-O-acyl-4-O-benzyl, or 4,6-O-benzylidene protecting groups was prepared. The conformationally flexible 3-O-acetylated glucosyl donor protected at other positions with O-benzyl groups demonstrated very low or no alpha-stereoselectivity upon glycosylation of primary or secondary acceptors. On the contrary, 3,6-di-O-acylated glucosyl donors proved to be highly alpha-stereoselective as well as the donor having a single potentially participating acetyl group at O-6. The 3,6-di-O-acylated donor was shown to be the best alpha-glucosylating block for the primary acceptor, whereas the best alpha-selectivity of glycosylation of the secondary acceptor was achieved with the 6-O-acylated donor. Glycosylation of the secondary acceptor with the conformationally constrained 3-O-acetyl-4,6-O-benzylidene-protected donor displayed under standard conditions (-35 degrees C) even lower alpha-selectivity as compared to the 3-O-benzyl analogue. However, increasing the reaction temperature essentially raised the alpha-stereoselectivities of glycosylation with both 3-O-acetyl and 3-O-benzyl donors and made them almost equal. The stereodirecting effects of protecting groups observed for N-phenyltrifluoroacetimidoyl donors were also generally proven for sulfoxide donors. (C) 2013 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.carres.2013.11.016