2000 Fiscal Year Final Research Report Summary
Synthesis of Geometrically Pure 11 Z-Retinal Derivatives for Elucidation of Visual Systems by Molecular Recognition
| Project/Area Number |
10480154
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Bioorganic chemistry
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| Research Institution | kyoto Pharmaceutical University (1999-2000)
Okayama University of Science (1998) |
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Principal Investigator |
UENISHI Jun'ichi Faculty of Pharmaceutical Science, kyoto Pharmaceutical University, Professor, 薬学部, 教授 (50167285)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Z-alkene / 11Z-retinal / Suzuki coupling / hydrogenolysis / stereospecific reaction / Geometrical control |
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| Research Abstract |
In this research, the following results were obtained during three years.
Stereocontrolled synthesis of 11Z-retinal by Suzuki coupling of C_1-C_<12> and C_<13>-C_<15> fragments
(1) Stereoselective hydrogenolysis of 1, 1-dibromo-1-alkene was performed by Pd catalyzed reduction with tributyltin hydride giving (Z)-1-bromo-1-alkene with excellent stereo-selectivity in good yield. A (Z)-bromotetraene corresponding to a C_1-C_<12> fragment of 11Z-retinal was prepared by this selective hydrogenolysis.
(2) Trisubstituted alkenylboronic acid corresponding to a C_<13>-C_<15> fragment of 11Z-retinal was prepared stereolselectively. These two fragments were coupled by Suzuki reaction catalyzed by Pd catalyst to give the complete 11Z-retinal skeleton. After transformation of terminal silyl ether to aldehyde gave stereochemically pure 11Z-retinal.
Stereocontrolled synthesis of 13-ehtyl substituted 11Z-retinal by Suzuki coupling of C_1-C_<10> and C_<11>-C_<15> fragments
(1) Trienylboronic acid corresponding to a C_1-C_<10> fragment of 11Z-retinal was prepared from dieneyne through idodotriene.
(2) Stepwise cross coupling reactions of 1, 1-dibromo-1-alkene by Sonogashira reaction and Kumada-Tamao reaction gave stereochemically pure trisubstituted enyne. Base on this method, 13-alkyl substituted iododiene corresponding to a C_<11>-C_<15> fragment of 11Z-retinal was synthesized.
(3) The two fragments were combined by Suzuki coupling to give 13-ethyl substituted 11Z-retinal skeleton under the stereocontrolled manner.
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