1986 Fiscal Year Final Research Report Summary
Development and Application of <C_2> -Symmetrically Substituted Pyrrolidine Chiral Auxiliaries
| Project/Area Number |
59470020
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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 |
天然物有機化学
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| Research Institution | Kyushu University |
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Principal Investigator |
YAMAGUCHI Masaru Professor, Faculty of Science, Kyushu University, 理学部, 教授 (60037140)
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| Co-Investigator(Kenkyū-buntansha) |
INANAGA Junji Assistant, Faculty of Science, Kyushu University, 理学部, 助手 (50091244)
KATSUKI Tsutomu Assistant, Faculty of Science, Kyushu University, 理学部, 助手 (40037271)
OKUKADO Nobuhisa Assistant Professor, Faculty of Science, Kyushu University, 理学部, 助教授 (40037213)
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| Project Period (FY) |
1984 – 1986
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| Keywords | 2,5-Disubstituted Pyrrolidines / <C_2> -Symmetry / Asymmetric Reaction / [2,3]Wittig Rearrangement / 立体選択的反応 / 〔2,3〕Wittig転位 |
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| Research Abstract |
Effective asymmetric reactions with 2,5-disubstituted pyrrolidines as chiral auxiliaries and related stereoselective reactions were developed.
The aldol condensation of the amide enolates derived from these amides, with aldehydes proceeded with high diastereo (>60:1) and diastereoface (>95% de) selectivities, when the corresponding zirconium enolates were used. Zirconium enolates derived from (E)-alkenyloxyacetyl amides, exhibited high level of syn-diastereo (>28:1) and diastereoface (>95% de) selectivities in their [2,3]Wittig rearrangement reaction. Zirconium mediated [2,3]Wittig rearrangement of (E)- <alpha> -alkenyloxyacetic acid esters was also performed with syn-diastereoselectivity (>50:1), high level of chirality transfer (-100%), and exclusive formation of (Z)-double bond. A combination of this [2,3]Wittig rearrangement reaction and Peterson reaction provided a highly stereoselective approach to (E,Z)- and (Z,Z)-dienes. Further, zirconium mediated enolate Claisen rearrangement was found to proceed through a boat-like transition state, differing from the usual [3,3]sigmatropic rearrangements which proceed through a chair-like transition state.
Some of these reactions were applied to the synthesis of natural products. Informations obtained through these studies are considered to contribute to the development of acyclic stereocontrol.
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