Inverse electron demand diels-alder reactions of psoralens. Synthesis and mass spectra of novel pyridazinocoumarins
作者:José Carlos González、Teresa Dedola、Lourdes Santana、Eugenio Uriarte、Michela Begala、Debora Copez、G. Podda
DOI:10.1002/jhet.5570370438
日期:2000.7
Diels-Alder reactions between the furan double bond of 8-methoxypsoralen and 1,2,4,5-tetrazine or 3,6-bistrifluoromethyl-1,2,4,5-tetrazine were accompanied by the release of diatomic nitrogen and the opening of the furan ring to leave a 6-pyridazinocoumarin. When 3,6-bis(methoxycarbonyl)-1,2,4,5-tetrazine was used as diene with 8-methoxy-, 5-methoxy- or 8-hydroxypsoralen as substrate a previously unknown
8-甲氧基补骨脂素与1,2,4,5-四嗪或3,6-双三氟甲基-1,2,4,5-四嗪的呋喃双键之间的狄尔斯-阿尔德反应伴随有双原子氮的释放和开放呋喃环的残基上留下一个6-pyridazino香豆素。当使用3,6-双(甲氧基羰基)-1,2,4,5-四嗪作为二烯并以8-甲氧基,5-甲氧基或8-羟基补骨脂素为底物时,创建了一个以前未知的杂环骨架。第四环的形成伴随着呋喃环向吡喃酮的转化,大概是通过分子内的酯基转移反应并释放了甲醇。讨论了通过详尽的质谱分析对这些反应的产物进行表征的方法。