194 Proceedings of the Royal Irish Academy. 



diveratrylidene-diacetoresorcinol diacetate is warmed with alcoholic potash, 



may be either tetraniethoxydiflavone (II) or diveratrylidene-dicoumaranone 



(III). 







(CE 3 0) 2 B 3 C 6 . C /\/\/\ C . C 6 B 3 (OCE 3 ) 2 



EC '^ J\/\/ CH 



CO CO 



O 



(CE s O) 2 B s Cc : C / in j \ C : CH . C„E 3 (OCB 3 ) 2 



CO CO 



It is only from analogy with the corresponding reactions in the mono- 

 flavone group and from the behaviour of the compound that it can be 

 determined whether the new compound is a derivative of diflavone or of 

 dicoumaranone. 



Flavones dissolve in concentrated sulphuric acid, giving colourless or 

 yellow solutions, with or without fluorescence ; while coumaranones, on the 

 other hand, with sulphuric acid, give orange or red solutions. 



A solution of diflavone in concentrated sulphuric acid has a light yellow 

 colour and a characteristic blue fluorescence. Since the diveratrylidene- 

 derivative, which we prepared, forms a deep violet-coloured solution in 

 concentrated sulphuric acid, its behaviour is similar to that of coumaranones, 

 and very unlike that of flavones or of diflavone. 



Moreover, in the monoflavone group, the chalkones derived from resaceto- 

 phenone and benzaldehyde can be converted into flavones, whereas those 

 derived from other aldehydes, such as anisaldehyde, form coumaranone 

 derivatives. 



There is a similarity between the structure of diveratrylidene-diacetoresor- 



cinol and that usually assigned to curcumin-dimethyl ether, which makes a 



determination of the tinctorial character of the diveratrylidene compound of 



interest. 



OCB 3 



Curcumin-dimethylether. 



.CO . CH : 



CB-/ 



VoCBj 



CB, 







N)0 . CB : 



CB-/ 



VOCE; 



— OCB3 









_OCB ? . 



CO . CB 



: CB-/ 



VOCE: 





\_ 



_/ 



C 6 B 2 (OB) 2 







NjO . CB 



: CB-/ 



VOCE: 



Diveratrylidenc-diacetoresorcinol. 

 VoCB 3 

 ^ OCE 3 



From analogy based on the structure of direct dyes in the nitrogen 



