1996 Fiscal Year Final Research Report Summary
Chiral Dienolate Chemistry in Remote Asymmetric Induction
| Project/Area Number |
07455357
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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 |
Synthetic chemistry
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
NAKAI Takeshi Tokyo Inst.Tech., Fac.Eng., Prof., 工学部, 教授 (90016717)
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| Co-Investigator(Kenkyū-buntansha) |
TOMOOKA Katsuhiko Tokyo Inst.Tech., Fac.Eng., Res., Assoc., 工学部, 助手 (70207629)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Asymmetric Synthesis / Remote Asymmetric Induction / Chiral Dienolate / Sigmatropic Rearrangement / Cope Rearrangement / oxy-Cope Rearrangement / Pd-Catalyst / Zaragozic acid A |
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| Research Abstract |
While the chiral auxiliary-based asymmetric induction constitutes the underlying principle most often utilized for asymmetric synthesis, the asymmetric induction at a position beyond the asymmetric environment imparted by the chiral auxiliary is, of course, extremely difficult. Conceptually, however, this problem could be solved by the proper combination in tandem of an asymmetric induction process within the asymmetric environment with an asymmetric transmission process to effect the net remote asymmetric induction.
To realize this concept, we designed a general synthetic approach which relies upon the chiral dienolate chemistry for the asymmetric induction followed by the sigmatropic process for the asymmetric transmission.
A summary of the research results is as follow :
(1) The allylation of the dienolate derived from the chiral alpha, beta- or beta, gamma-unsaturated imide followed by the Cope rearrangement is shown to effect the net remote asymmetric induction to create a new chirality of either configuration at the gamma-position in high % de. The utility of this approach is shown in the asymmetric synthesis of the C6 side chain of zaragozic acid A.
(2) The asymmetric aldol reaction of the boron dienolate derived from chiral alpha, beta- or beta, gamma-unsaturated imide followed by the siloxy-Cope rearrangement is shown to provide the gamma, delta-anti-or-syn-alpha, beta-unsaturated imide as the main product.
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