新型还原oxy-Nazarov环化反应研究

发布时间：2018-02-25 17:09

本文关键词： oxy-Nazarov 5-羟基环戊烯酮 1 3-二氧杂环戊-2-酮苯并1 4二氧杂环己-2-酮　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：经典Nazarov环化反应是构建多官能团取代的五元碳环的周环反应，但因其区域选择性与立体选择性的控制等问题，使得该反应在有机合成中的应用具有一定的局限性。我们课题组发展了具有广泛底物适用性的多种类型的还原oxy-Nazarov电环化新方法，具有以下特点：（1）立体专一性的构筑多取代、多官能团化的羟基环戊烯酮；（2）通过在环化底物中引入C2对称的手性二醇为辅基，可有效实现不对称的还原oxy-Nazarov环化反应（Scheme1）。本论文第一部分针对1984年Ramage等报道（J. Chem. Soc., Perkin Trans. I1984,1531-1537）的1,3-二氧杂环戊-2-酮（1,3-dioxolan-2-one）衍生物在二异丁基氢化铝还原条件下反应研究的实验结果进行了重复与验证。我们将肉桂醛的Wittig反应生成的构型异构体（2-24E）和（2-24Z）经柱色谱分离纯化后，分别在二异丁基氢化铝还原条件下反应，，发现只有EE构型异构体发生立体专一性的还原环化反应，生成反式构型的4-苯基-5-羟基-环戊烯酮产物（2-25），从而确证了早期文献报道中推测的环化产物是oxy-Nazarov电环化反应的结果（Scheme2）。本文第二部分描述了研究了一种新型的由邻苯二酚衍生的1,4-二氧杂环己-2-酮（benzo[b]-1,4-dioxin-2-one）环化前体（2-31）的设计、合成及在二异丁基氢化铝还原条件下立体专一性的生成环化产物（2-34）的oxy-Nazarov电环化反应研究（Scheme3）。
[Abstract]:The classical Nazarov cyclization reaction is a ring reaction of constructing a five-member carbon ring replaced by multifunctional groups. However, due to the control of its regioselectivity and stereoselectivity, the application of the reaction in organic synthesis is limited to a certain extent. Our group has developed a variety of new reduction oxy-Nazarov electrocyclization methods with extensive substrate applicability, with the following characteristics: 1) the construction of stereospecific substitution. The asymmetric reduction of oxy-Nazarov cyclization reaction can be realized effectively by introducing C2 symmetric chiral diol into the cyclized substrate. In the first part of this thesis, we repeat and verify the experimental results of the reaction of Ramage et al., J. Chem. Soc., Perkin Trans. I1984, 1531-1537) in the reduction condition of diisobutyl aluminum hydride. The configuration isomers of cinnamaldehyde produced by Wittig reaction were separated and purified by column chromatography. Under the reduction conditions of diisobutyl aluminum hydride, only EE isomers were found to have stereospecific reductive cyclization. A trans-configuration of 4-phenyl-5-hydroxy-cyclopentenone was obtained. It was confirmed that the cyclization product in the early literature was the result of oxy-Nazarov electrocyclization. In the second part of this paper, we describe the design of a new cyclization precursor, benzo [b] -1n 4-dioxin-2-one, derived from catechol. Oxy-Nazarov electrocyclization of cyclization product of stereospecific synthesis and reduction of diisobutyl aluminum hydride under the condition of stereospecific cyclization.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R914

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