2016 Fiscal Year Final Research Report
Total Synthesis of (+)-ascospiroketals A,B and Determination of there Absolute Configurations
| Project/Area Number |
26460028
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Chemical pharmacy
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| Research Institution | Tokushima Bunri University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | ascospiroketal / 1,4-addition reaction / asymmetric aldol / diastereo selective / ganmma-lactone / beta-lactone / decarboxylation / organic synthesis |
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| Outline of Final Research Achievements |
The synthesis of (+)-ascospiroketal B commenced from 2-propyn-1-ol, namely, Negishi iodomethylation of 2-propyn-1-ol followed by protection of hydroxy group by TBDPS and coupling reaction with (S)-2-phenyloxazolidinone accompanied insertion of CO catalyzed by Pd(PPh3)4 afforded 1. Then 1 was treated with vinyl copper reagent and converted to 2 in high diastereoselectivity. The aldol reaction of 2 accompanied by removal of oxazolidinone moiety to form b-lactone ring gave β-lactone 3 as a single isomer. Methylation of 3 with MeLi followed by ozonolysis and PDC oxidation produced γ-lactone 5 in good yields. Although Bayer-Viliger oxidation of 5 with usual reagent such as mCPBA did not proceeded due to the steric strain around methylketone．
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| Free Research Field |
有機合成化学
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