The Use of Grignard Reagents in the Synthesis of Carbohydrates. III. The One-way Anomerization of Methyl Glycofuranosides and the Opening of Their Furanose Rings
The Use of Grignard Reagents in the Synthesis of Carbohydrates. III. The One-way Anomerization of Methyl Glycofuranosides and the Opening of Their Furanose Rings
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格氏试剂在碳水化合物合成中的应用。
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
S. Emoto
中科院分区：
文献类型：
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作者：
M. Kawana;H. Kuzuhara;S. Emoto
甲基呋喃糖苷衍生物与甲基碘化镁或叔丁基溴化镁的端基异构化反应以单向方式进行。例如，当3β和叔丁基溴化镁的苯-乙醚混合物在约75 °C下加热以除去乙醚时，甲基5-O-苄基-β-D-呋喃核糖苷（3β）以95%的产率转化为相应的α-端基异构体（3α）;逆反应（从3α到（3β））没有进行。3β与甲基碘化镁反应，除3α（30%）外，还生成开链产物（33%）。对20种端基异构体进行了测试，并对反应机理进行了讨论。在反应过程中还观察到用格氏试剂裂解苄基或三苯甲基保护基。
The anomerization of methyl glycofuranoside derivatives with methylmagnesium iodide or t-butylmagnesium bromide occurred in a one-way manner. For example, methyl 5-O-benzyl-β-D-ribofuranoside (3β) was converted into the corresponding α-anomer (3α) in a 95% yield when a mixture of 3β and t-butylmagnesium bromide in benzene–ether was heated at about 75 °C to remove the ether; the reverse reaction (from 3α to (3β) did not proceed. The reaction of 3β with methylmagnesium iodide gave open-chain products (33%), besides 3α (30%). Twenty kinds of anomers were tested, and the mechanisms of the reactions were discussed. The cleavage of a benzyl- or trityl-protecting group with the Grignard reagent was also observed during the reaction.