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全碳链的亲双烯与共轭双烯间的Diels-Alder反应的立体化学、区域选择性及反应机理已得到较系统的研究。但对含硫原子亲双烯的Diels-Alder反应研究得还不多,1968年Ohne等报道了硫酮与2-位取代双烯的D-A反应,1-位取代双烯与硫酮的D-A反应尚未见报道。二苯甲硫酮(1)作为亲双烯体,它与共轭双烯可以通过一步D-A反应,得到含硫六元杂环化合物。本文选择了有代表性的反-1-苯基-1,3-丁二烯(2a)、反-2,4-戊二烯酸甲酯(2b)和反-1,3-戊二烯(2a)作为共轭双烯,它们分别与二苯甲硫酮在黑暗中,氮气保护下进行D-A反应,得到定量的两种立体异构的加成产物3和4。将加成物分别氧化后,得到相应的氧化物
The stereochemistry, regioselectivities and reaction mechanism of Diels-Alder reaction between the d-diene and conjugated diolefins have been systematically studied. Diels-Alder reaction of sulfur-containing dienophiles has not been studied yet. In 1968, Ohne et al. Reported the DA reaction of thione with 2-substituted dienes and the DA reaction of 1-substituted diolefins with thione Not yet reported. Benzhydrothiophenone (1), as dienophile, can react with conjugated diene through one-step D-A reaction to obtain sulfur-containing six-membered heterocyclic compounds. In this paper, we selected the representative trans-1-phenyl-1,3-butadiene (2a), methyl trans-2,4-pentadienoate (2a) as conjugated dienes, respectively, which were subjected to DA reaction with benzthiophenone in the dark under the protection of nitrogen to give quantitative two stereoisomeric addition products 3 and 4, respectively. The adducts were oxidized, respectively, to obtain the corresponding oxide