クマリン誘導体の研究 (第15報)

オルシノールと2位に置換基をもつアセト酢酸エステルとの縮合生成物について

抄録

The structure of the product obtained by the condensation of orcinol and 2-substituted acetoacetic ester is either 7- or 5-hydroxycoumarin derivative. The literatures published to date claim that it is a 5-hydroxycoumarin derivative with the exception of the condensate from 2-benzylacetoacetic ester. However, such conclusions were based on the fact that the solutions of the condensate in conc. sulfuric acid and sodium hydroxide do not show any fluorescence and direct proof of their structures has not been made. By the comparison of ultraviolet absorption spectra of 7- and 5-hydroxycoumarin with those of the condensate of orcinol and 2-substituted acetoacetic esters, it was proved that all the condensates are 5-hydroxycoumarin derivatives. Moreover, it was proved that the condensate of orcinol and 2-benzylacetoacetic ester was 3-benzyl-4, 7-dimethyl-5-hydroxycoumarin and not the 7-hydroxy compound as reported in past literature.