76 Mr Ruhemann, Studies on Unsaturated Ketonic Compounds. 



Studies on Unsaturated Ketonic Compounds. By S. Ruhemann, 

 M.A., Gonville and Caius College. 



[Bead 27 February 1905.] 



In a paper which I lately published in the Journal of the 

 Chemical Society (1905, lxxxvii. 17) it has been shown that, 

 under the influence of bases, olefinic ketonic compounds react 

 with mercaptans to form additive substances only. On using as 

 catalytic agent hydrogen chloride alone or together with zinc 

 chloride, Posner (Ber. xxxiv. 1395 ; xxxv. 799) has found that 

 frequently mixtures are produced owing to the fact that mer- 

 captans, besides reacting additively at the ethylene linking, partly 

 condense with the ketonic group of the olefinic ketones. In the 

 paper referred to, I have described various additive products of 

 olefinic ketonic compounds containing the grouping 



I 

 CH : CH— CO— . 



I 

 I have since applied this reaction to other substances of the same 

 type of ketones and have obtained from benzylideneacetophenone, 

 benzylidenedesoxybenzoin, benzylidenebenzoylacetic ester the fol- 

 lowing compounds. 



Benzylideneacetophenone yields with zso-amylmercaptan, under 

 the influence of piperidine, iso-amylthiolbenzylacetophenone, 



C 6 H 5 . CH (S . C 5 H U ) . CH 2 . CO . C 6 H 5 , 



which melts at 49 — 50° ; with phenylmercaptan the ketone forms 



C 6 H 5 .CH(S.C 6 H 5 ).CH 2 .CO.C 6 H 5 (m.p. 120—121°). 



The latter substance is identical with the substance which Posner 

 has prepared by the aid of hydrogen chloride as catalytic agent ; 

 but from iso-amylmercaptan and the olefinic ketone he has obtained 

 an oil which from the analytical result he concludes to be a 

 mixture. 



Benzylidenedesoxybenzoin unites with phenylmercaptan to 

 yield phenylthiolbenzyldesoxybenzoine, 



C 6 H 5 .CH(S.C 6 H B ).CH(C 6 H 5 ).CO.C 6 H 5 (m.p. 204—205°). 



