Synthesis and Thermal Rearrangement of 4-Heterohepta-1,2,5,6-tetraenes
Synthesis and Thermal Rearrangement of 4-Heterohepta-1,2,5,6-tetraenes
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4-杂七-1,2,5,6-四烯的合成与热重排
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
V. Rumjanek
中科院分区：
文献类型：
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作者：
Y. P. Cheng;P. Garratt;S. Neoh;V. Rumjanek
4-杂庚烷-1，6-二炔在碱催化下可在严格控制的条件下重排成相应的4-杂庚烷-1，2，5，6-四烯。这些四烯化合物的热重排通过一个速率决定步骤为一级的过程得到了相应的二聚体。测定了这些反应的速率常数，并用假定的双自由基中间体的芳香族贡献来解释相对速率。在所调查的两个案例中，发现当在3O2存在下进行热分解时，会形成环状过氧化物系。
4-Heterohepta-1,6-diynes can be rearranged by base catalysis under carefully controlled conditions to the corresponding 4-heterohepta-1,2,5,6-tetraenes. Thermal rearrangment of these tetraenes gives the corresponding dimers by a process in which the rate-determining step is first order. The rate constants for these reactions have been determined and the relative rates accounted for in terms of an aromatic contribution afforded to the presumed diradical intermediates. In the two cases investigated it was found that when the thermolyses were conducted in the presence of 3O2 then cyclic peroxides were formed.