AlgaK — Unsaturated Ketones derived from Diaceto-Orcinol. Ill 



Whereas resorcinol under similar conditions forms resacetophenone. 



HO/\OH 



I I 

 \/C0.CH3 



The general properties of the ketones described in this communicatiotl 

 closely resemble those of similar ketones prepared from diacetoresorcinol 

 (Eyan and O'Neill, loc. cit.) ; but efforts to obtain diflavone or diflavanone 

 derivatives from them did not meet with success. When the diacetate of 

 dibenzylidene-diaceto-orcinol was brominated, a certain amount of hydro- 

 bromic acid gas was eliminated, and when the product was heated with 

 alcoholic potash, a small amount of a brownish amorphous substance separated 

 which did not crystallise, and did not show any of the properties of a 

 diflavone derivative. Similar treatment of dibenzylidene-diacetoresorcinol 

 readily gives colourless crystals of diflavone. When the same reaction was 

 tried with dianisylidene-,diveratrylidene-,and dipiperonylidene-diaceto-orcinol 

 there seemed to be no formation of diflavone or dieoumaranone compounds. 

 An effort was made to prepare diflavanone derivatives by allowing a mixture 

 of diaceto-orcinol and benzaldehyde or anisaldehyde to stand for some days 

 in the presence of alcoholic hydrochloric acid. 'J'he results were, however, 

 negative, and further attempts to prepare these compounds were hampered 

 by the difliculty of obtaining a supply of orcinol. 



During the preparation of dipiperonylidene- diaceto-orcinol two isomeric 

 substances were isolated, one of which melts at 236°-237"' (J. and the other 

 at 248-249" (!. The former is referred to as a-dipiperonylidene- diaceto- 

 orcinol, and the latter as j3-dipiperonylidene-diaceto-orcinol. The /3 com- 

 ppund is apparently produced from the a compound by the action of warm 

 hydrochloric acid. The a derivative dissolved in potash, but the /3 derivative 

 seemed to be entirely insoluble. It is, therefore, possible that the /3 compound 

 has either of the flavanone formulae I or II. 



CO.CH:CH.C6H3:OjCH2 CHj CO 



I /-\ 



HO/V/XCH.CcHsiOjCHj CH2O2: CeHj.CH \ /\/\CH . (JsHs : OjCHj 

 I I I I I II I I 



\/\/CH, \/\/CH, 



CH3 CO CH3 CO 



the formula of the a compound being : — 



CO.CH:CH.C6H3:02CH2 



H0/\ OH 



I I 



\/C0 . CH : CH . CeHs : O2CH2 



CH3 

 Owing to the small amount of the |3 compound isolated, it was impossible 

 to further examine the substance with a view to determining its constitution. 



[S2| 



