1988 Fiscal Year Final Research Report Summary
Application of Weak Coordination Concerning Calcium-Multidentate Ligand Complexes
| Project/Area Number |
62470089
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Synthetic chemistry
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| Research Institution | Keio University |
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Principal Investigator |
YOSHIKAWA Sadao Professor of Keio University, 理工学部, 教授 (70010759)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMURA Shuuichi Assistant Professor of Keio University, 理工学部, 助教授 (30051874)
OSANAI Shuuichi Assistant Professor of Keio University, 理工学部, 助教授 (70051828)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Aldohexose / Epimerization / Ethylenediamine / Calcium / Monoamine / Glucose / モノアミン / ニッケル |
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| Research Abstract |
The development of methods whereby metals promote transformation of sugars is of considerable interest.
We have recently reported the novel epimerization of aldoses promoted by the combination of Nickel and diamines, which proceeds rapidly under the mild basic condition.
This time, various kinds of N-alkyl substituted ethylenediamine derivatives were prepared to study the effects of ligand on the epimerization. The introduction of more hydrophobic long alkyl groups at nitrogen atom affects the amphibility of the complex which plays an important role in the reaction.
Among the ligands, N,N'-dialkylethylenediamine showed the most active ability for C-2 epimerization of glucose and mannose, which attained equilibrium in a few minutes under methanol reflux. The equilibrium points between C-2 epimer could be moved to glucose side by using the longer alkyl chain.
The ^<13>C NMR studies of Nickel-diamine system using ^<13>C enriched D-glucose revealed that C-2 epimerization involves the novel sterospecific rearrangement of carbon skelton.
Moreover, epimerization of aldoses were examined using calcium ions. The characteristics of calcium ions were the effectiveness of mono amine in contrast with the fact that no C-2 epimerization was observed in the Ni^<2+>- monoamine system.
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