Mr Ruhemann, Studies on Unsaturated Ketonic Compounds. 77 



Ethyl benzylidenebenzoylacetate forms with phenylmercaptan 

 the additive compound 



C 6 H 6 . CH (S . C 6 H 5 ) . CH (CO . C 6 H 5 ) . C0 2 . C 2 H 5 (m.p. 100—101°). 



In my previous communication (loc. cit.) I have pointed out 

 that di-olefinic ketones of the type : 



II II 



C : C— CO— C : C 



I I 



combine with 1 or 2 mols. of mercaptans, whilst, by the aid of 



hydrogen chloride as catalytic agent, Posner has been able to 



obtain only additive products with 2 mols. of mercaptans. I have, 



further, shown that cinnamylideneacetophenone, a di-olefinic ketone 



of the type : 



I I I I 

 C : C— C : C— CO— 



I 

 unites with 1 mol. only of either iso-amylmercaptan or phenyl- 

 mercaptan. This result differs from Posner's statement (Ber. 

 xxxvu. 502) according to which the substance resulting from 

 the reaction between the ketone and phenylmercaptan is an 

 additive compound with 2 mols. of the mercaptan. Prof. Posner 

 has since by letter corrected his error. 



Cinnamylideneacetone, C 6 H 5 . CH : CH — CH : CH . CO . CH 3 , 

 also unites with 1 mol. of phenylmercaptan only to form a com- 

 pound which melts at 53 — 54°. But Posner's pupil, A. Werner 

 (see Posner, loc. cit), has found that the product of the action of 

 hydrogen chloride on a mixture of the ketone and the mercaptan, 

 is an oil which, by potassium permanganate, is transformed into 

 a di-sulphone. From this result it would follow that the oil is an 

 additive product of the di-olefinic ketone with 2 mols. of the 

 mercaptan ; yet my experiments, recorded in this paper, and the 

 facts at which Kuvevenagel (Ber. xxxvu. 4038) arrived in the 

 course of his study on the reaction of potassium hydrogen sulphite 

 with di-olefinic ketones of the above type, induce me to doubt 

 the correctness of Werner's result. 



The behaviour of mercaptans towards the tri-olefinic ketone, 

 Ginnamylidenebenzylideneacetone, 



C 6 H 5 . CH : CH . CH : CH . CO . CH : CH . C 6 H 5 , 



is similar to the action of mercaptans on cinnamylideneacetone or 

 cinnamylideneacetophenone. With 1 mol. of either phenylmer- 

 captan or iso-amylmercaptan it yields additive compounds which 

 melt at 69 — 70° and 133 — 134° respectively. The ketone, also, 

 adds 2 mols. of mercaptans, but I have been unable to isolate 



