1089 



into pinacoliri, a considerable quantity of a hydrocarbon is obtained 

 here in addition to a pinacoiin. A foi-niatc of the pinacone could 

 not be isolated. 



If we treat pinacone from inethylethylketone with an equal weight 

 of 97 7o fo'''nic acid, the li(iui(l, particularly on warming', tui-ns a 

 beautiful red colour and after about a (piarter of an hour's heating 

 in a waterbath, the homogeneous mixture sepai'ates into two layers, 

 the upper one of which is nearly colourless. The bottom layer which 

 has a dark red colour gives, when diluted with water, a pale coloured 

 supernatant layer. The united laj'ers were washed with water and 

 dried over potassium carbonate. On distilling at the ordinary pres- 

 sure up to 150° a liquid was obtained which proved to consist 

 mainly of the pinacoiin (CH3), . CJl- . C . CO . C^H^. 



The residue was distilled in vacuo when as main product was 

 obtained a pale yellow viscous liquid b. p. 130°. By fractionating 

 over metallic sodium a colourless distillate with an agreeable odour 

 was finally obtained. (/V'-' = 0.8741; n\-^'' = 1.4864. MRd = 72.3 



* 4 J ) 



calculated for C,« H,, fr 72.9. 



The elementary analysis gave: C 86.96, 87.16; H 13.J7, 12.827„. 

 Calculated for C,„ H,, : C 87.27, H 12.72 7„. 



The determination of the molecular weight (by means of the 

 lowering of the freezing point of benzene) gave 216.3 and 207; 

 calculated for C,, H,, 220. 



Herschmann ^) found that by the action of concentrated sulphuric 

 acid at 0° pinacoiin occurs only, but on heating with 5 °\ sulphuric 

 acid was formed, besides pinacoiin, also a hydrocarbon C^ R^^ b. p. 

 117° — 121°, which, as noticed by us, is converted on heating with 

 formic acid into a dimeride identical with our hydrocarbon 0,^ H^a- 



CH, CH3 CII3 CH, 



CH, CH. _oii.,,, CH CH 



I I ' ^ II II -^(C.H^J,. 



HOCH CHOH CH — CH 



II II 

 CH3 CH3 CH3 CH 



One might imagine the structure of the hydrocarbon C,g H^^ to 

 be like that of an octomethylcyclo-octadiene : 



1) Monalshefte 14, -238 (1893). 



71* 



