Das Elektronenspektrum eines vinylogen Tropons (Die photochemische darstellung des 2-Hydroxy-guaj-azulens)
作者:R. Hagen、E. Heilbronner、P. A. Straub
DOI:10.1002/hlca.19670500837
日期:——
Irradiation of guaj-azulene-2-sulfonic acid (VII) in 40 percent aqueous or methanolic sulfuric acid with light of 370 nm wave-length yields 2-hydroxy-guaj-azulene (V) or 2-methoxy-guaj-azulene (X) respectively. The former compound (V) exhibits a keto-enol tautomerism V ⇋ VI, the equilibrium constant of which is strongly dependent on solvent. The keto form VI contains the π-electron system of a vinylogue
在370 nm波长的光下,在40%的硫酸水溶液或甲醇中,对guaj-azulene-2-磺酸(VII)进行辐照,生成2-羟基-guaj-azulene(V)或2-甲氧基-guaj-azulene(X ) 分别。前一种化合物(V)表现出酮-烯醇互变异构体V⇋VI,其平衡常数强烈依赖于溶剂。酮形式VI包含乙烯基托普酮IV的π电子体系。使用PARISER-PARR-POPLE类型的CI模型对VI的电子光谱进行理论分析,可支持先前提出的在托普酮(I),苯甲酸托酮(II)和萘萘酮(III)中观察到的电子跃迁的分配。