— 145 — 



acids, passes over immediately, with loss of water, into suberane 



aldehyde 



CH^ CH CH\ 



I )CH.CHO 



CH 2 CH 2 CH/ 



which is of particular interest being the first synthetic aldehyde of 

 a 7 -ring system. The oxime, from which the aldehyde could be 

 regenerated, distilled over between 110 and 120 , but could not be 

 made to crystallise. The semicarbazone of the aldehyde melted at 

 153 to 1 54 . By oxidation with silver oxide this yielded then the 

 silver salt of heptamethylene carboxylic acid. As a by-prcduct of the 

 permanganate oxidation there is formed oxysuberane carboxylic acid 

 (m. p. 7 8°), which was identified by its difficultly soluble sodium salt. 

 The conversion of methene suberene into the corresponding aldehyde 

 is accomplished in the following phases: 



(C 6 H 12 ) (C 6 H 12 ) (C 6 H 12 ) (C 6 H 12 ) 



C = CH 2 C(OH)CH 2 .(OH) C^CH-OH CH-CHO 



methene suberene glycol (unstable) suberane aldehyde 



The nitrosochloride of methene suberene yields on treatment with 

 sodium methylate, with loss of hydrochloric acid, an oxime, which 

 produces by means of sulphuric acid the unsaturated suberene aldehyde, 



C EL • C H 2 • C H <v 



I )C.CHO, 



CHg -CH 2 .CH/ 



which is converted by oxidation into the corresponding acid, suberene 

 carboxylic acid (m. p. 50 to 51 ). According to this, the nitrosochlorides 

 or nitrosates of the methene compounds can also be used for the 

 production of unsaturated alicyclic aldehydes, the same as they have 

 already for a long time been employed for producing unsaturated 

 ketones. 



Cyclohexanone. 1 ) Whilst 1,3-methyl-cyclohexanone was already 

 made accessible 10 years ago by Wallach 2 ) by splitting up pulegone, 

 this was with i,2-and-i,4-methyl cyclohexanones only accomplished by 

 the well-known reduction-method of Sab a tier. All three ketones 

 have a similar odour; the boiling points increase (though but slightly) 

 with the distance of the two atom-groups CH 3 and CO. The specific 

 gravity is fairly equal in 1,3- and 1,4-methylhexanone, but is higher in 

 1,2-methylhexanone. The capacity of auto-condensation varies; with 



*) Wallach, Liebig's Annalen, 346 (1906), 24Q. 



*) Comp. Reports October 1896, 92; April 1897, 56; October 1904, 127. 



