2011 Fiscal Year Final Research Report
Efficient Synthesis of the alkyl chains with multiple stereogenic centers
| Project/Area Number |
21655035
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Synthetic chemistry
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| Research Institution | Waseda University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
TATSUTA Kuniaki 早稲田大学, 名誉教授・栄誉フェロー (40051627)
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| Project Period (FY) |
2009 – 2011
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| Keywords | 有機合成化学 / 不斉合成 / 鎖状化合物 / ポリケチド / 遠隔不斉誘導 |
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| Research Abstract |
Two subjects shown below have been successfully performed.
(1) Development of remote asymmetric induction methodologies by using chiral vinylketene N, O-acetals
The chiral vinylketene N, O-acetal, derived from α-methyl-α,β-unsaturated imide, was found to give syn adduct stereoselectively by the Lewis-acid mediated aldol reaction with acetals. The same N, O-acetal also gave syn adducts by reaction with aldehyde and excess amount of TiCl_4. This N, O-acetal has already known to afford anti adducts stereoselectively by reacting with aldehyde and one equivalent of TiCl_4.Therefore, we established stereo-divergent synthesis ofδ-alkoxy-γ-methyl-α,β-unsaturated imide by choosing amount of TiCl_4.The chiral vinylketene N, O-acetal has reacted with acid anhydrides to proceed acylation, the 1, 6-asymmetric induction reaction. Additionally, the chiral vinylketene N, O-acetal without the α-methyl group also performed the remote asymmetric induction.
(2) Synthesis of polyketide haing multiple stereogenic centers
The adducts of the remote asymmetric induction reaction mentioned above have been submitted to the regio-and stereoselevtive reduction to give methyl-branched fatty acids with desired stereochemistry.
The adduct of the chiral vinylketene N, O-acetal and an α-methyl-α,β-unsaturated aldehyde has both allylic alcohol and the α,β-unsaturated imide. Taking advantage of the adduct, we have realized the regio-and stereoselective reduction and established the short step synthesis of reducted polyketide chains.
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