methyl 2-deoxy-4,6-O-benzylidene-α-D-galactopyranoside | 221662-13-1

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡喃二恶英
• 英文名称: methyl 2-deoxy-4,6-O-benzylidene-α-D-galactopyranoside
• 英文别名: methyl 4,6-O-benzylidene-2-deoxy-α-D-galactopyranoside；4,6-O-Benzyliden-methyl-2-desoxy-α-D-galaktopyranosid；(2S,4aR,6S,8R,8aR)-6-methoxy-2-phenyl-4,4a,6,7,8,8a-hexahydropyrano[3,2-d][1,3]dioxin-8-ol
• CAS: 221662-13-1
• 化学式: C₁₄H₁₈O₅
• 分子量: 266.294
• InChiKey: FHXCXDUEKHFWGP-RGDJUOJXSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.8
• 重原子数：
  19
• 可旋转键数：
  2
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.57
• 拓扑面积：
  57.2
• 氢给体数：
  1
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  methyl 2-deoxy-4,6-O-benzylidene-α-D-galactopyranoside 在 4-二甲氨基吡啶 、 偶氮二异丁腈 、 三正丁基氢锡 作用下， 以 二氯甲烷 、 甲苯 为溶剂， 反应 5.0h， 生成 Methyl-(4,6-O-benzyliden-2,3-didesoxy-β-D-erythro-hexpyranosid)
  参考文献：
  名称：

  溴代二甲基溴化溴催化从半乳糖中合成2-Dexoy-4,6-O-亚苄基半乳糖吡喃半乳糖和快速合成2,3-和2,6-二脱氧吡喃半乳糖的途径

  摘要：

  4,6- ø的-Benzylidenation d -galactal用的PhCH（OCH 3）2由bromodimethylsulfonium溴化物引线催化以2- dexoy -4,6- ø -亚苄基半乳糖苷有效地，其用作一个关键中间体的准备准备2,3-和2,6-二脱氧半乳糖吡喃糖苷。

  DOI：

  10.1002/cjoc.201180487
• 作为产物：
  描述：

  苯甲醛二甲缩醛 、 (2R,3R,4R)-2-(羟基甲基)-3,4-二氢-2H-吡喃-3,4-二醇 在 溴化二甲基溴化锍 作用下， 以 丙酮 为溶剂， 反应 0.17h， 生成 methyl 2-deoxy-4,6-O-benzylidene-α-D-galactopyranoside 、 methyl 4,6-O-benzylidene-2-deoxy-β-D-lyxo-hexopyranoside
  参考文献：
  名称：

  溴代二甲基溴化溴催化从半乳糖中合成2-Dexoy-4,6-O-亚苄基半乳糖吡喃半乳糖和快速合成2,3-和2,6-二脱氧吡喃半乳糖的途径

  摘要：

  4,6- ø的-Benzylidenation d -galactal用的PhCH（OCH 3）2由bromodimethylsulfonium溴化物引线催化以2- dexoy -4,6- ø -亚苄基半乳糖苷有效地，其用作一个关键中间体的准备准备2,3-和2,6-二脱氧半乳糖吡喃糖苷。

  DOI：

  10.1002/cjoc.201180487

文献信息

• Ring Contraction vs Fragmentation in the Intramolecular Reactions of 3-O-(Trifluoromethanesulfonyl)pyranosides. Efficient Synthesis of Branched-Chain Furanosides
  作者：Mohamed Kassou、Sergio Castillon

  DOI：10.1021/jo00119a011

  日期：1995.7

  Intramolecular reactions of several methyl 3-O-triflylpyranosides of gluco, manno, galacto, and arabino (2-deoxy-gluco) configuration are studied. Triflates 1b-6b, of gluco, manno, and 8-deoxy-gluco configuration, give rise to ring-contraction products (branched-chain furanosides) 12, 15, 16, 17, 19, and 20, respectively. Triflates 7b and 10b of galacto configuration give the fragmentation products 21 and 23, whereas the 2-deoxy-galacto derivative 8b leads to ring-contraction product 20, which shows the decisive influence of the configuration at position 4 and the presence of a 2-alkoxy group on the reaction process. When the results from 4,6-O-benzylidene derivatives (1b-8b) and 4,6-di-O-benzyl derivatives (91b-11b) are compared, it turns out that the presence of a 4,6-O-benzylidene protecting group favors the formation of ring-contraction products. The use of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent and pyridine or 2,6-di-tert-butyl-4-methylpyridine as the base allowed us to obtain good to excellent yields of ring-contraction or fragmentation products.
• ——
  作者：Tarikere L. Gururaja、Paloth Venugopalan、Michael J. Levine

  DOI：10.1023/a:1021864511771

  日期：——

  Synthesis of methyl 2-azido-2-deoxy-4,6-O-benzylidene-beta-D-galactopyranoside (1), one of the key components in the synthesis of O-glycoamino acids, was undertaken in order to synthesize Tn and TF(3) antigen building blocks. In pursuit of an alternative approach, benzylidenation of the crude D-galactal (2a) afforded methyl 2-deoxy-4,6-O-benzylidene-alpha-D-galactopyranoside (3c) and 3,4-O-benzylidene-D-galactal (3b) besides the expected 4,6-O-benzylidene-D-galactal (3a). Formation of compound 3c was explained based on the presence of methyl 2 deoxy-alpha-D-galactopyranoside (2b) isomer and/or trace amount of methanol in the crude mixture of deacetylated product of 2 prior to benzylidenation. On the other hand, formation of 3b in substantial quantities appears to be a thermodynamically controlled product and its formation is found to be common during prolonged Lewis-acid catalyzed benzylidenation reaction. Crystal structures of these important and useful precursors were deduced by X-ray diffraction methods to enumerate their complete molecular structure as well as to understand the effect of the cyclic acetal on the pyranose ring conformation. Compound 1 crystallizes in the orthorhombic space group P2(1)2(1)2(1) With cell dimensions a = 5.058(7), b = 12.766(7), c = 22.557(7) Angstrom; 3b crystallizes in the hexagonal space group P6(1) with cell dimensions a = 18.265(4), b = 18.265(3), c = 6.323(2) Angstrom; 3c crystallizes in the monoclinic space group P2(1) with cell dimensions a = 10.614(3), b = 4.963(2), c = 12.730(3) Angstrom, and beta = 95.47(3)degrees.
• Bromodimethylsulfonium Bromide Catalyzed Synthesis of Methyl 2-Dexoy-4,6-O-benzylidene Galactopyranoside from Galactal and the Rapid Route to 2,3- and 2,6-Dideoxygalactopyranoses
  作者：Ning Ding、Yuexing Chun、Wei Zhang、Yingxia Li

  DOI：10.1002/cjoc.201180487

  日期：2012.2

  4,6‐O‐Benzylidenation of D‐galactal with PhCH(OCH3)2 catalyzed by bromodimethylsulfonium bromide leads to methyl 2‐dexoy‐4,6‐O‐benzylidene galactopyranoside efficiently, which serves as a key intermediate to the ready preparation of 2,3‐ and 2,6‐dideoxy galactopyranosides.

  4,6- ø的-Benzylidenation d -galactal用的PhCH（OCH 3）2由bromodimethylsulfonium溴化物引线催化以2- dexoy -4,6- ø -亚苄基半乳糖苷有效地，其用作一个关键中间体的准备准备2,3-和2,6-二脱氧半乳糖吡喃糖苷。