Ryan and Dunlea — On Unsaturated 0-Btke tones. — I. 3 



According to this method we found that although cinnamic ester 

 condensed with acetone and acetophenone to form respectively cinnamyl- 

 acetyl-methane, and cinnamyl-benzoyl-methane 

 C 6 H 6 CH : CH . COOC 2 H 5 + CH 3 . CO . CH 3 = C 6 H S CH : CH . CO . CH 2 . CO . CH 3 



+ C 2 H 5 OH . 

 C 6 H S CH : CH . COOC 2 H 5 + CH 3 . CO . C 6 H 5 = C 6 H 5 CH : CH . CO . CH 2 . CO . 



C 6 H 5 + C 2 H 5 OH, 

 yet we were unable to obtain the same compounds from benzylidene-acetone, 

 with acetic or benzoic ester, e.g. 



C 6 H 5 . COOC 2 H 5 + CH 3 . CO . CH : CH . C 6 H 5 = C 6 H 5 CO . CH 2 CO . CH : CH . 



C 6 H 5 + C 2 H 5 OH 

 The condensation of the unsaturated ester with the saturated ketone proceeds 

 normally, but the condensation of a saturated ester with an unsaturated 

 ketone — an apparently analogous reaction —proceeds in quite a different and 

 at present undetermined direction. Similarly the attempt to prepare the parent 

 substance of curcumin, mentioned above, by the condensation of cinnamic ester 

 with benzylidene-acetone led to the formation of no new crystalline product. 



The two unsaturated diketones showed the usual reactions of such bodies, 

 e.g., their alcoholic solutions were coloured by ferric chloride, and they were 

 precipitated by carbon dioxide from their solutions in dilute alkali. They 

 colour wool mordanted with iron alum a strong red, with dichromate a dark 

 yellow, and with aluminium sulphate a faint yellow. Like the chalkones, 

 they dissolve in concentrated sulphuric acid to orange-coloured solutions, and, 

 like curcumin, they react with hydroxylamine hydrochloride to form 

 isoxazols. 



The question of condensation in the case of mixed alkyl ketones was also 



investigated. As examples we took methyl-ethyl-ketone and methyl- 



isopropyl-ketone. Both yield, with cinnamic ester, colourless crystalline 



products, closely resembling each other in their behaviour. In both cases 



alternate formulae are possible. Thus the diketone from cinnamic ester and 



ethyl-methyl-ketone may be either 



C 6 H 5 CH : CH . CO . CH (CH 3 ) . CO . CH 3 I. 



Or, 



C 6 H 5 CH : CH . CO . CH 2 . CO . CH, . CH 3 II. 



whilst that from cinnamic ester with methyl-isopropyl-ketone may be either 



C 6 H 5 CH : CH . CO . C(CH 3 ) 2 . CO . CH 3 I. 



Or, 



/CH 3 

 C 6 H 6 CH : CH . CO . CH 2 . CO . CH 



\CH 3 II. 



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