The Cycloaddition of Dispiro[2.2.2.2]deca-4,9-diene with the Styrene Derivatives. The Syntheses and Spectral Properties of the [4.2]Paracyclophane Derivatives
作者:Tohru Shibata、Takashi Tsuji、Shinya Nishida
DOI:10.1246/bcsj.50.2039
日期:1977.8
cycloaddition of dispiro[2.2.2.2]deca-4,9-diene 1 with the styrene derivatives has afforded [4.2]paracyclophane derivatives, 3. A reaction mechanism by way of the biradical intermediates, involving the initial homolytic cleavage of the cyclopropane ring in 1 followed by the addition to the styrene molecule, is proposed. In the reaction of 1 with styrene, and methyl α-phenylacrylate, the yields of 3 were improved
二螺[2.2.2.2]deca-4,9-二烯1与苯乙烯衍生物的热环加成得到[4.2]对环芳烷衍生物,3.通过双自由基中间体的反应机制,包括环丙烷的初始均裂建议在 1 中加入环,然后添加到苯乙烯分子中。在1与苯乙烯和α-苯基丙烯酸甲酯的反应中,3的产率随着反应物的稀释而提高,而在与反式二苯乙烯的反应中,没有观察到对反应物浓度的明显依赖性。取代的 [4.2] 对环芳烃的质谱显示主要裂解为取代的对二甲苯-α,α'-二基(或其元素)离子自由基。[4. 2]Paracyclophane 表现出依赖于温度的 NMR 谱,这可以归因于两个结构等效的构象异构体之间的快速平衡。C-1 和 C-2 上的大量取代基使平衡向一侧移动。