Michael Addition of Various Nitrogen and Oxygen Nucleophiles to 1,1-Diethoxybut-3-yn-2-one
作者:Leiv Sydnes、Myagmarsuren Sengee
DOI:10.1055/s-0031-1289294
日期:2011.12
furnish a Michael addition product, but catalyzes a trimerization that leads to formation of a 6H-1,3-dioxine derivative. When bis-nucleophiles, for instance hydrazine and hydroxylamine, are used, the Michael-addition products are unstable and undergo secondary reactions to form heterocyclic compounds, which are isolated in excellent yields. acetylenic ketones - Michael additions - vinyl ketones - cyclotrimerization
1,1-二乙氧基丁-3-yn-2-one,一种共轭的末端炔酮,与氮和氧亲核试剂反应,生成迈克尔加合物,在大多数情况下,收率良好至极佳。在几乎每种情况下,主要反应是单加成反应,从而导致形成立体定向方式形成相应的β-取代的α,β-不饱和酮。立体化学取决于亲核试剂的性质,通常的模式是氨和伯胺产生Z-烯酮,而仲胺和醇产生E-烯酮。三乙胺不提供迈克尔加成产物,但催化三聚反应,导致形成6 H-1,3-二恶英衍生物。当使用双亲核试剂,例如肼和羟胺时,迈克尔加成产物不稳定并且经历二次反应以形成杂环化合物,其以优异的产率被分离。 炔酮-迈克尔加成-乙烯基酮-环三聚-乙缩醛