| Project/Area Number |
63550616
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
有機工業化学
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| Research Institution | Chiba University, Faculty of Engineering |
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Principal Investigator |
YAMAMOTO Makoto Chiba Univ., Fac. Eng. (Ass. Professor), 工学部, 助教授 (50039294)
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| Co-Investigator(Kenkyū-buntansha) |
KOHMOTO Shigeo Chiba Univ., Fac. Eng. (Assistant), 工学部, 助手 (90195686)
YAMADA Kazutoshi Chiba Univ., Fac. Eng. (Professor), 工学部, 教授 (60009230)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Organotin Compound / LTA Cyclization / Radical Cyclization / Epoxy-allylic Tin Compound / Thionolactone Synthesis / Stereoselective Cyclization / Tandem Cyclization / 立体選択的環化反応 |
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| Research Abstract |
The following results were obtained from the study of "Stereoselective Cyclisation Reactions Using Organotin Compounds".
1). By the oxidative substitution reactions of organotin compounds with LTA gave corresponding oxygen-functionalized one. This oxidation was applied to the synthesis of 4-ylidenebutenolides. Treatment of 5-stannyl-1,3-pentandiol derivatives with LTA gave 4-hydroxytetrahydropyran in good yield. The diol which has a double or a triple bonds in its molecule were further cyclized to a polycyclic ether. The cyclization of 3-hydroxy-5-stannyl- pentanoic acid yielded 4-hydroxy-delta-lactone.
2). The radical cyclization of xanthates using tri-n-butyltin hydride gave a thionolactone which was easily oxidized to its lactone. The diastereo- selectivity of the cyclization was well controlled (de> 95%). The linear xanthates having two kinds of radical acceptor sites also cyclized to multifused thionolactone (Tandem radical cyclization).
3). Lewis-acid induced regio- and stereoselective cyclization of epoxy-allylic stannanes was also carried out. The cyclization proceeded in good yield, and the regioselectivity of the cyclization was governed by the stability of the carbocation which was formed. The stereochemistry around the epoxide carbons was also discussed.
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