p-tolyl 2,3-di-O-methyl-4,6-methylidene-β-D-thioglucopyranoside | 753490-97-0

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: p-tolyl 2,3-di-O-methyl-4,6-methylidene-β-D-thioglucopyranoside
• CAS: 753490-97-0
• 化学式: C₁₆H₂₂O₅S
• 分子量: 326.414
• InChiKey: QJHVUICDOBXMAD-LJIZCISZSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.21
• 重原子数：
  22.0
• 可旋转键数：
  4.0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.62
• 拓扑面积：
  46.15
• 氢给体数：
  0.0
• 氢受体数：
  6.0

反应信息

• 作为反应物：
  描述：

  溶剂黄146 、 p-tolyl 2,3-di-O-methyl-4,6-methylidene-β-D-thioglucopyranoside 在 N-碘代丁二酰亚胺 作用下， 以 1,2-二氯乙烷 为溶剂， 反应 72.0h， 生成 acetyl 2,3-di-O-methyl-4,6-methylidene-β-D-glucopyranoside 、 1-acetyl 2,3-di-O-methyl-4,6-methylidene-α-D-glucopyranoside
  参考文献：
  名称：

  The Disarming Effect of the 4,6-Acetal Group on Glycoside Reactivity:  Torsional or Electronic?

  摘要：

  An evaluation of whether the well-known deactivating effect of a 4,6-acetal protection group on glycosyl transfer is caused by torsional or an electronic effect from fixation of the 6-OH in the tg conformation was made. Two conformationally locked probe molecules, 2,4-dinitrophenyl 4,8-anhydro-7-deoxy-2,3,6-tri-O-methyl-beta-D-glycero-D-gluco-octopyranoside (18R) and the L-glycero-D-gluco isomer (18S), were prepared, and their rate of hydrolysis was compared to that of the flexible 2,4-dinitrophenyl 2,3,4,6-tetra-O-methyl-beta-D-glucopyranoside (21) and the locked 2,4-dinitrophenyl 4,6-O-methylidene-2,3-di-O-methyl-beta-D-glucopyranoside (26). The rate of hydrolysis at pH 6.5 was 21 > 18R > 18S > 26, which showed that the deactivating effect of the 4,6-methylene group is partially torsional and partially electronic. A comparison of the rate of acidic hydrolysis of the corresponding methyl a-glycosides likewise showed that the probe molecules 17S and 17R hydrolyzed significantly slower than methyl tetra-O-methyl-glucoside 19, confirming a deactivating effect of locking the saccharide in the C-4(1) conformation. The experiments showed that the hydroxymethyl rotamers deactivate the rate of glycoside hydrolysis in the order tg much greater than gt > gg.

  DOI：

  10.1021/ja047578j
• 作为产物：
  描述：

  p-tolyl 4,6-O-benzylidene-2,3-di-O-methyl-1-thio-β-D-glucopyranoside 在 盐酸 、 sodium hydroxide 、 四丁基碘化铵 作用下， 以 1,4-二氧六环 、 甲醇 为溶剂， 反应 6.0h， 生成 p-tolyl 2,3-di-O-methyl-4,6-methylidene-β-D-thioglucopyranoside
  参考文献：
  名称：

  The Disarming Effect of the 4,6-Acetal Group on Glycoside Reactivity:  Torsional or Electronic?

  摘要：

  An evaluation of whether the well-known deactivating effect of a 4,6-acetal protection group on glycosyl transfer is caused by torsional or an electronic effect from fixation of the 6-OH in the tg conformation was made. Two conformationally locked probe molecules, 2,4-dinitrophenyl 4,8-anhydro-7-deoxy-2,3,6-tri-O-methyl-beta-D-glycero-D-gluco-octopyranoside (18R) and the L-glycero-D-gluco isomer (18S), were prepared, and their rate of hydrolysis was compared to that of the flexible 2,4-dinitrophenyl 2,3,4,6-tetra-O-methyl-beta-D-glucopyranoside (21) and the locked 2,4-dinitrophenyl 4,6-O-methylidene-2,3-di-O-methyl-beta-D-glucopyranoside (26). The rate of hydrolysis at pH 6.5 was 21 > 18R > 18S > 26, which showed that the deactivating effect of the 4,6-methylene group is partially torsional and partially electronic. A comparison of the rate of acidic hydrolysis of the corresponding methyl a-glycosides likewise showed that the probe molecules 17S and 17R hydrolyzed significantly slower than methyl tetra-O-methyl-glucoside 19, confirming a deactivating effect of locking the saccharide in the C-4(1) conformation. The experiments showed that the hydroxymethyl rotamers deactivate the rate of glycoside hydrolysis in the order tg much greater than gt > gg.

  DOI：

  10.1021/ja047578j