— 146 — 



benzaldehyde 1,2-methylhexanone condenses to a bright-yellow oil (prob- 

 ably a monobenzylidene compound); i,3-and-i,4-methylhexanone yield 

 deep-yellow dibenzylidene compounds. The boiling point of 1,2-methyl- 

 hexanone lies at 164 to 165 , a fact which has been confirmed not 

 only by Wallach, but also by Sabatier and W. H. Perkin; d 0,926; 

 n D20° !>4493; oxime, m. p. 43 to 44 . For 1,4-methylhexanone the 

 following constants were observed: b. p. 169 to 171 ; d 0,914; 

 n D20° I >443 1 5; its oxime melts at 37 to 39 and boils at 114 (14 mm. 

 pressure). With 2 mol. benzaldehyde the ketone condenses to a di- 

 benzylidene compound of the m. p. 98 to 99 . From a further work by 

 Wallach 1 ) on the two isoximes of 1,3-methylcyclohexanone it appears 

 that to the a-isoxime the formula belongs given further down. It was 

 namely found that this body, when boiled with hydrochloric acid, 

 splits up, with formation of the hydrochloride of an amido acid, which on 

 oxidation with permanganate in alkaline solution yields /?-methyl adipic 

 acid (m. p. 86°). The following formulae may represent the progress 

 of the conversion: — 



CI^ . CHfCHg) • CH 2 v CH 2 . CH(CH 3 ) ■ CH 2 . COOH 



I >CO -► I 



CH^ .CH 2 — NH/ CH 2 .CH 2 . NH 2 



a-isoxime amido acid 



CH 2 • CH(CH 3 ) • CH, • COOH 



CH 2 .COOH 



/?-methyladipic acid 



The ^J-isoxime was split up into the amido acid by boiling with 

 hydrochloric acid, and the hydrochloride of the acid, from which the 

 excess of acid had been removed as much as possible, yielded after 

 treatment with sodium nitrite and oxidation of the hydroxy acid formed 

 with permanganate, in addition to bicarboxylic acids, a keto acid 

 whose semicarbazone melted at 177 , and which is identical with 

 7-acetyl-butyric acid. The reaction is as follows: — 



CHjCHlCHgJCH,. CH 2 CH(CH 3 )CH 2 NH 2 



I * )NH -> I 



CH 2 CH 2 CO/ CHjjCIijCOOH 



/?-isoxime amido acid 



CH 2 CH(CH 3 )CH 2 OH CH 2 CH (CH,) COOH CH, COCH 3 



CH^CI^COOH CH 2 CH 2 COOH CI^C^COOH 



hydroxy acid y-acetyl-butyric acid 



J ) Liebig's Annalen 309 (1899), 2; 312 (1900), 194; 332 (1904), 348. 



