High-Order Use of Reactive Intermediates Stabilized by Oxygen Atom

氧原子稳定的反应中间体的高阶使用

• 批准号: 05671752
• 负责人: FUJIOKA Hiromichi
• 金额: $ 1.09万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05671752/
• 关键词: cationic species; intermediate in Beckmann fragmentation; endo-brevicomin; d-(R)-lipoic acid; dioxenium cation; orthoester; polyol; polysubstituted tetrahydrofuran; 幼若フェロモン; α-(R)-lipoic酸; 多置換テトラヒドロピラン; cationic species; intermediate in Beckmann fragmentation; endo-brevicomin; d-(R)-lipoic acid; dioxenium cation; orthoester; polyol; polysubstituted tetrahydrofuran; 幼若フェロモン; α-(R)-lipoic酸; 多置換テトラヒドロピラン

In this project, we studied on high-order use of i) the reactive intermediates in Beckmann fragmentation reaction and ii) the dioxenium cations formed by acid treatment of orthoesters.i) The Beckmann fragmentation is one of the long-known reactions and used widely in organic synthesis. Although the reactive intermediates in the Beckmann fragmentation of the corresponding alpha-alkoxycycloalkanone oxime derivatives are very active electrophiles, only a limited kind of nucleophiles such as H2O,ROH,halide anion and carbon ones have been used so far. As the organic synthesis utilizing the intermediates of Beckmann fragmentation, we developed new carbon-carbon bond forming reactions using silicon-containing carbon nucleophiles and organoaluminium reagents. As an extention of the reactions, we also succeeded in developing a novel asymmetric carbon-carbon bond formation by combination of Beckmann fragmentation reaction and asymmetric synthesis using a chiral acetal and a highly stereoselective carbon-carbon bond formation in the reaction of 2,3-isopropyridenedioxycyclohexanone oxime esters with organpaluminium reagents.ii) Orthoesters work as superior electrophiles by forming dioxenium cations We succeeded in a facile one-pot formation of oxacyclic compounds in the reaction of triols with trialkyl orthoesters in the presence of acid catalyst. The reaction was successfully applied to the unprotected high-order alcohols giving polysubstituted tetrahydrofurans in a one-pot synthesis.

在该项目中，我们研究了i）贝克曼碎裂反应中的反应性中间体和ii）二氧化剂阳离子是由酸处理矫形器形成的。尽管相应的α-烷氧基氧烷酮氧电衍生物的贝克曼碎片中的反应性中间体是非常活跃的电力，但到目前为止，仅使用了一种有限的亲核试剂，例如H2O，ROH，Halide阴离子和碳。随着有机合成利用贝克曼碎片的中间体，我们使用含硅核友菌和有机铝菌试剂开发了新的碳碳键反应。作为反应的扩展，我们还成功地通过贝克曼碎片反应和不对称合成的结合使用手性乙酰乙酸和高度立体的碳碳键形成，在2，3-异丙基二氧甲氧甲甲甲氧甲烯丙基甲烯丙克西酮中的反应中结合使用贝克曼碎片反应和不对称合成形成新型不对称的碳碳键形成2，3-异丙烯氧甲甲氧烷氧氧氧化物的反应中的反应中，我们还成功地开发了一种新型的不对称碳 - 碳键形成矫形器通过形成二恶英阳离子作为上电钻，我们成功地在酸催化剂的存在下，在三一个与试验甲醇的反应中，在三醇与试验甲醇的反应中取得了成功的一锅形成。该反应成功地应用于未受保护的高阶醇中，在一锅合成中提供了多卵巢四氢呋喃。