PROCEEDINGS 



OF 



THE ROYAL IRISH ACADEMY 



PAPERS READ BEFORE THE ACADEMY 



I. 



ON UNSATUEATED /3-DIKETONES.— I. 

 By Prof. HUGH BYAN, D.Sc, and Eev. J. M. DUNLEA, B.Sc. 



Read June 23. Published August a, 1913. 



It is a remarkable fact that, although most of the naturally occurring dyes 

 are free from nitrogen and owe their tinctorial properties to unsaturated 

 ketonic groups, yet, for many years, chemists in their synthetic work 

 have confined themselves almost exclusively to the field of nitrogenous 

 derivatives. 



This neglect of the chemistry of natural bodies seems hardly justifiable, 

 especially in view of its undoubted theoretical interest. 



We have therefore undertaken a study of the unsaturated polyketones, 

 with the object in the first place of synthesizing some of them, and in the 

 next of determining the influence of different radicles upon their chromatic 

 properties. In the present paper we are concerned mainly with diketones. 



It has been shown by von Kostanecki and his co-workers that many of 

 the yellow plant-dyes are derivatives of flavone or flavonol. For instance, 

 from flavone we have the yellow chrysin, and from flavonol we have, similarly, 

 quercetin. These, like many other plant-dyes, may be regarded as 

 unsaturated ketones ; flavonol, for instance, containing the grouping 



. CO . C : 6 . 

 OH 



to which in conjunction with the ortho-hydroxyls it owes its tinctorial 

 character. 



B.I. A. PEOC, VOL. XXXII., SECT. B. [B] 



