1987 Fiscal Year Final Research Report Summary
Syntheses of Highly Oxygenated Terpenic Plant Toxins
| Project/Area Number |
60470029
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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 | TOHOKU UNIVERSITY |
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Principal Investigator |
YOSHIKOSHI Akire Chemical Research Institute of Non-Aqueous Solutions, Tohoku Univ., 非水溶液化学研究所, 教授 (20006290)
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| Co-Investigator(Kenkyū-buntansha) |
MIYASHITA Masaaki Chemical Research Institute of Non-Aqueous Solutions, Tohoku Univ., 非水溶液化学研究所, 助手 (50006326)
KIDO Fusao Chemical Research Institute of Non-Aqueous Solutions, Tohoku Univ., 非水溶液化学研究所, 助手 (20006315)
KATO Michiharu Chemical Research Institute of Non-Aqueous Solutions, Tohoku Univ., 非水溶液化学研究所, 助教授 (00006305)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Plant toxins / Anisatin / Coriamyrtin / Picrotoxinin / Picrotin / 高度に酸化されたテルペン |
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| Research Abstract |
1) Synthesis of Anisatin: In order to explore the synthetic route of anisatin, a model synthesis was first examined. 5-Hydroxy-5-methy1-2-oxaspiro[3.5]nonane involring <beta>-lactone r ing structurally most characteristic in anisatin was selected as the model substance and its efficient synthetic route was established. Relating to this synthesis, reductive cleavage of oxetanes was also studied, and it was found that the neighboring participation of the hydroxyl group was assisted ready regioselective cleavage of oxetanes. In addition, a new and practical synthesis of 6-oxo-1-cyclohex- enecarboxylates, which has been regarded as a useful starting material for the anisatin synthesis, was devised.
2) Synthesis of Coriamyrtin: In this study, the <beta>-vinylbutenolide annulation strategy was planned to be employed, and a new and general synthetic method of the requisite <gamma>-alkyl-<alpha>-phenylthio-<beta>-vinylbutenolides was found.
3) Synthesis of Picrotoxanoids: The synthesis of picrotoxinin starting from 1- carvone was accomplished in a highly selective manner through ca. 30 steps resulting in high overall yield. A new transformation of picrotoxinin into picrotin was completed in much more efficient manner than that of the known procedure. Relating the synthesis of picrotoxinin, a new method for redioselectivr reductive cleavage of <alpha>,<beta>-epoxy ketones (and esters) was found. Sodium benzeneselenolate is an excellent reagent for this reduction giving the corresponding <beta>-hydroxy ketones (or esters), and its general applicability was observed. As an application of this reduction, some selinane sesquiterpene lacotnes were synthesized. The reactive species in this reduction was also found to be Na^+[C_6H_5SeB(OC_2H_5)_3]^-.
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