Flash vacuum pyrolysis at 1000-1100°C of the allyl esters of the three
isomeric biphenylcarboxylic acids, of the allyl esters of the 12
biphenyldicarboxylic acids and of the three biphenyldicarboxylic anhydrides
gave pyrolysates which were examined by 1H n.m.r.
spectroscopy at temperatures below -50°C. In all cases the spectra showed
the presence of cyclopent[a]indene and
acenaphthylene together with other products. Possible mechanisms for these
ring contraction and cyclization processes are discussed and the results of
pyrolyses of [2,3-13C2]
biphenyl-2,3-dicarboxylic anhydride, and
[3,4-13C2]- and
(2-2 H1)-biphenyl-3,4-dicarboxylic
anhydrides are reported.
在 1000-1100°C 下闪速真空热解三种异构联苯羧酸的烯丙基酯
在 1000-1100°C 下闪速真空热解三种异构联苯羧酸的烯丙基酯、12
联苯二甲酸的烯丙基酯和三种联苯二甲酸酐的烯丙基酯
得到的热解产物通过 1H n.m.r.
光谱进行了检测。在所有情况下,光谱都显示
存在环戊并[a]茚和
苊烯和其他产物。这些
环收缩和环化过程的可能机制进行了讨论,并对
2,3-13C2]的热解结果。
联苯-2,3-二羧酸酐和
[3,4-13C2]和
(2-2 H1)-联苯-3,4-二羧酸酐的热解结果。
酐。