100 REPORTS ON THE STATE OF SCIENCE. 



solution of magnesium methyl iodide and the product decomposed with 

 water, when trimethylcyclohexanol (V) was obtained as a well-defined, 

 crystalline substance, melting at 72°'5. 



oMe <ci:7c c H 2 > cH 2 --> cM ^<gg:^i ( ^>cH 2 



(IV) (V) 



rM .CH, . CMeBr xnTT 

 GMe *<CH 2 CH 2 > CH2 



(VI) 



Fuming hydrobromic acid converts the alcohol into 3-bromo-l : 1 :3- 

 trimethylcyclohexane (VI), which, when treated with alcoholic potas- 

 sium hydroxide, loses the elements of hydrogen bromide in two ways, 

 giving rise to the same mixture of hydrocarbons as described by 

 Tiemann. The identity was established by preparing the crystalline 

 nitrosate, and from it the oxime described by Wallach 6 ; further by 

 oxidising the hydrocarbons with potassium permanganate, when the 

 products isolated were as-dimethylsuccinic acid, zsogeronic and geronic 

 acids. 



1: 1: 2-Trimethylcyclohexan-3-one.* Brief reference was made 

 in the last Beport 7 to the method adopted for the preparation of this 

 ketone, the object of its isolation being to compare its properties with 

 those of camphor on account of the marked similarity of the various 

 groupings in the molecules of these two ketones. Further, it was 

 thought that a more extended inquiry into the chemical behaviour of 

 trimethyldihydroresorcin than has hitherto been carried out was desir- 

 able because, unlike dimethyldihydroresorcin (VII), its molecule is not 

 symmetrical, and consequently several new points of interest are raised. 

 This latter problem has proved to be more complicated than was antici- 

 pated, but there can be no doubt that trimethyldihydroresorcin is a 

 tautomeric substance, exhibiting the two forms represented by formulas 

 VII and VIII 



C(CH 3 ) 2 C(CH 3 ) 2 



H 2 C f) CH.CH 3 H 2 C A CH.CH 3 



OC ^ C.OH HO.C ' v CO 



CH CH 



(VII) (VIII) 



the particular form manifested depending on the nature of the reagents 

 with which the dihydroresorcin is brought in contact. As a result, 

 In the series of reactions which give rise to 1 : 1 : 2-trimethylcyclo- 

 hexan-3-one, both 1:1: 2-trimethylcyclohexan-3-ol and 1:1: 2-tri- 

 methylcyclohexan-5-ol are formed, both of which alcohols are capable 

 of existing in cis and trans modifications, but so far only the trans form 



5 Annalen, 1902, 324, 97. 



« Crossley and Renouf, J.C.S., 1911, 99- 



7 Brit. Assoc. Beport, Sheffield, 1910, p. 82. 



