226 



l{EPORtS ON TfiE STATE OF SCIENCE. 



the Grignard reaction from broraohexahydrobenzene, was conveftecl into 

 the corresponding iodide, and this latter body heated with alcoholic potash. 



HjC 



CH, 



CH, 



Tl.fi .J CH, 



C^CH., 

 (1) 



Bfi 



HjC 





CH, 



CH 



C . CH 



(II) 



HjC 



H.,C 



CH, 



CH, 



.y CHj 



COH . CH,OH 

 (III) 



tt,C 



H.,C 



CH, 



CH„ 



i^^' CH, 



CH .CBO 

 (IV) 



Methylenecycloliexane absorbs two atoms of bromine, and the resulting 

 dibromide gives, on warming with 10 per cent, potassium carbonate 

 solution, the glycol having formula III. When treated with very dilute 

 sulphuric acid this glycol gives an aldehyde (IV), which can also be 

 obtained directly from the dibromide by treatment with lead oxide and 

 water. These facts conclusively prove the constitution of the dibromide 

 and of the hydrocarbon. 



Methylenecyclohexane is unaltered on boiling with quinoline, but is 

 converted l)y a mixture of quinoline and quinoline-hydriodide into the 

 isomeric methyltetrahydrobenzene (11). This fact would account for the 

 hydrocarbon obtained by Zelinsky and Gutt from the iodide of cyclo- 

 hexylcarbinol by heating with quinoline, being a mixture of the two 

 isomerides. 



Auwers ' has shown that the alcohols V and VI, prepared from the 

 ketone VII by Grignard's reaction, lose water to give unstable inter- 

 mediate products, which readily pass into benzene derivatives. Thes« 

 reactions 



CII, CHCl., CH, CHCl,, CH3 . CHCl, 



\/ ' \/ \/ 



/\ /\ /\ 



II 



O 



(Vll) 



/\ 



Ho CH3 

 (V) 



/\ 



HO CHo.CH^ 



(VI) 



have been very fully investigated, and are described in detail in this 

 lengthy memoir. The hydroaromatic alcohols V and VI and their homo- 

 logues are not very stable substances, and inany, if not all, exist in two 

 modifications, probably due to cis- and <>'a?is-isomeri3m. The above- 

 mentioned intermediate products are considered to be alkylidenedihydro- 

 benzenes, 



CH, CHCl., CH, CHCL 



\/ 



OH CH, 



\, 



II 

 oHj 



the general chemical and physical properties of which substances are 

 ' Annalen, 1907, 352, 219, 273, 288. 



