— 9 o — 



Whereas the oxidation of phellandral into an acid with an equal 

 number of carbon atoms only proves the aldehyde character, oxidation 

 tests with permanganate gave some explanation as to its constitution. 

 5 gm. aldehyde were treated with a 3 per cent, permanganate solution 

 at ordinary temperature, until no further discolouration took place. 

 After driving off with water- vapour any portions which might not yet 

 have become oxidised, the liquid filtered off from the manganese slime 

 was evaporated to about 200 cc, and then acidified with sulphuric 

 acid. A slight turbidity now occurred, and after a few hours about 

 0,1 gm. crystals separated off, from which the liquid was filtered off. 

 As the bulk of the oxidation product must have been dissolved in 

 water, the liquid was repeatedly extracted with ether, and by these 

 means an acid was abstracted which solidified soon after evaporation 

 of the ether. After recrystallisation from water or benzene-petroleum 

 ether, it melted at 70 to 7 2°. The acid readily dissolves in the 

 usual organic solvents, and is only insoluble in light petroleum. 



9,0966 gm. of the substance: 0,2030 gm. C0 2 ; 0,0732 gm. H 2 0. 



Found Calculated for C 9 H 16 4 



C 57,3% 57,4% 



H 8,4% 8, 5 o/ 



The silver -salt of the acid dissolves with difficulty in water. 



0,3736 gm. of the substance: 0,3658 gm. C0 2 ; 0,1154 gm. H 2 0; 



0,2012 gm. Ag. 

 Found Calculated for C 9 H 14 4 Ag 2 



C 26,7<>/ 26,7% 



H 3,52% 3,43% 



Ag 53,7% 53,8%; 



The principal product of the oxidation with permanganate is there- 

 fore a dibasic acid C 9 H 16 4 . The above mentioned crystalline acid 

 which is difficultly soluble in water, melted, after being recrystallised 

 twice from dilute alcohol, at 11 5° to 11 6°. Owing to scarcity of 

 material, no examination could be made with regard to the character 

 of this acid. 



The formation of an acid C 9 H 16 4 from the aldehyde C 10 H 16 O 

 is explained most simply by accepting a tetrahydrated benzene-nucleus, 

 in which the double-linking is situated in the /?, ^-position towards 

 the aldehyde-group. The oxidation gives no information with regard 

 to the side-chain, but the optical activity of the aldehyde requires 

 an asymmetric carbon atom. In view of the odour which reminds in 

 a pronounced manner of cuminic aldehyde, it may not be improbable 

 that the new aldehyde is a tetrahydrated cuminic aldehyde (p-isopropyl- 

 tetrahydrobenzaldehyde). 



