1988 Fiscal Year Final Research Report Summary
Exploration of New Methodologies for Construction of Carbocycles their Synthetic Application
| Project/Area Number |
62470019
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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 |
有機化学一般
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
KUWAJIMA Isao Department of Chemitsry, A Faculty of Science, 理学部, 教授 (50016086)
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| Co-Investigator(Kenkyū-buntansha) |
URABE Hirokazu Department of Chemistry, A Faculty of Science, 理学部, 助手 (10176745)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Cortisone / 3-(Silylmethyl)cyloalkenones / Taxane / One-Carbon Ring Enlarged Reactions / 2ー(シリルメチル)シクロアルカノン |
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| Research Abstract |
We have investigated on new methodologies for construction of cyclic carbon frameworks either from (1) acyclic precursors and (2) cyclic ones.
(1) Generation of new nucleophilic species as metal homoenolates has been established, and several types of selective carbon-carbon bond forming reactions have been explored. These results can be applied for construction of steroidal carbon frameworks, and we succeeded to develop a useful methodology for a total synthesis of cortisone, involving a short and useful method for introduction of its side chain. Further, a useful methodology for construction of taxane ring system has also been developed. (2) Starting from 1-(TMS-methyl)cycloalkanecarbaldehydes and their derivatives, one-carbon ring expansion reactions involving cationic carbon skeleton rearrangement have been investigated. On generating carbocationic species stabilized by several hetero atoms, the ring carbon undergoes rearrangement selectively to afford the corresponding one-carbon ring enlarged products in high yields. Further, reactions of unsymmetrically substituted substrates have been studied, and migratory aptitude of a substituent has been proved as the following order: a sp^2-carbon > a more-substituted sp^3-carbon > a less-substituted sp@>D13@>D1-carbon.
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