| Project/Area Number |
13640541
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Organic chemistry
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
KAMIGATA Nobumasa Graduate School of Science, Department of Chemistry, Professor, 理学研究科, 教授 (70087112)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2001: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Optically Active Seleninic Acid / Optical Resolution / Circular Dichroism Spectra / Chiral Crystallization / Absolute Configuration / X-ray Crystallographic Analysis / X線結晶構造解析 / 光学活性カラム / ラセミ化機構 |
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| Research Abstract |
It has been considered that the optical resolution and isolation of enantiomers of seleninic acid as a stable compound are very difficult since optical active seleninic acid will be easily racemized by a trace amount of the water and there is no good technique for the optical resolution until recently. We have succeeded in isolation of optically active areneseleninic acid by kinetic stablization with bulky substituent and unisng chromatographic resolution with chiral column for the first time. However, the optically active areneseleninic acids were racemized during the removal of the solvent, and therefore we could not isolated the enantiomer of areneseleninic acid. Benzeneseleninic acid possessing crown ether was synthesized and optically resolved by chiral crystallization from methanol/toluene. Thus, optically pure enantiomee of benzeneseleninic acid derivative was succeeded, and the absolute configuration was determined by X-ray crystallo-graphic analysis. The absolute configurations of optically acive areneseleninic acids resolved by chromatography was determined by comparison their CD spectra.
Optical Resolution of several kind of seleninic acid (RSeO_2H : R=Me, i-Bu, neopentyl, cyclohexyl, Ph) by chiral crystallizatin was also tried. Enantiomeric pure compound was obtained in the case of methaneseleninic acid. The absolute configuration of enantiomeric pure methaneseleninic acid showing negative Cotton effect around 250 nm in the CD spectra was S-form by X-ray crystallographic analysis and hence that of positive Cotton effect around 250 nm was R-form. The optically pure methanesleninic acid was immediately racemized and became optically inactive when it was dissolved in solvent in spite of a slightly remaining water in the solvent was chromatographic resolution, however which was more unstable for racemization than the corresponding seleninic acids.
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