Commercial and scientific notes on essential oils. 35 



however, under greatly diminished pressure it is possible to isolate the piperitone in 

 its natural, markedly lasvorotatory form ([«] D — 42.8 ) 1 ). 



A specimen of piperitone obtained by Read and Smith from the essential oil of 

 Eucalyptus dites by distillation under atmospheric pressure and by purification by 

 means of neutral sodium sulphite, showed the constants:— b. p. 128.5° (25 mm.), 

 [«] D — 0.27°, n D20 o 1.4843; hydroxylamino-oxime, m. p. 169 to 170°; oxime, m. p. 110 to 

 111°; semicarbazone, m. p. 219 to 220°. (The semicarbazone prepared by Wallach 2 ) 

 from z^-p-menthenone-S had the m. p. 224 to 226°.) On treating piperitone with benz- 

 aldehyde in presence of metallic sodium the authors obtained benzylidene-d, ^-piperitone 

 C 10 H 14 : CH • C 6 H 5 , m. p. 61°; oxime, m. p. 130 to 131°. 



The bimolecular ketone C20H34O2 from piperitone obtained by Baker and Smith, 

 under the identical conditions, yielded no benzylidene compound. 



From the oil of Eucalyptus hemiphloia, R. T. Baker and H. G. Smith 3 ) succeeded in 



obtaining a new crystallised phenol which they termed australol. This phenol, which 



occurs also in other oils of the "Boxes", was prepared in the same manner as tasmanol 



(comp. Report 1916, 30) and showed the following constants: — in. p. 62°, b. p. 115 to 



116° (10 mm.), d 20O 0.9971, « D + 0, n D20 o 1.5195, mol. refr. found 41.50; calculated for 



three double bonds 41.74; benzoate, m. p. 72 to 73°. In alcoholic solution, ferric 



P Qw, chloride gave with the phenol a fleeting greenish yellow colour 



at first, quickly changing to bright yellow. The odour of australol 



HCi iCH 2 reminded of ordinary phenol, and the skin was attacked by the 



H pi |qj new phenol in exactly the same manner as by phenol. Combustion 



'"%/ and molecular weight determination proved the empirical formula 



CCH 2 -CH:CH 2 C 9 Hi 2 0. Since the unsaturated phenol gave no colour reaction 



Probable structure w jth picric acid, the unsaturated side-chain has most probably 



of australol. f, ' .' . . 



the allyl grouping, two double bonds thus occurring in the 

 nucleus. The authors conclude, therefore, that australol is a dihydro-p-allylphenol 

 of the structure given above. 



From the oil of Eucalyptus hemiphloia and related eucalypts, Baker and Smith 

 obtained formerly 4 ) an aldehydic body which they termed aromadendral. Recently 5 ) 

 it was found that this body, which occurs likewise in the oils of the "Box" and "Mallee" 

 group, was no uniform substance, but a mixture of aromadendral proper, Ci Hi 4 O, with 

 cuminal Ci Hi 2 O, phellandral Ci Hi 6 O and a new aldehyde "cryptal" Ci Hi 6 O. The 

 latter aldehyde had escaped the authors in their first investigation, because it did 

 not form a solid compound with sodium bisulphite, and the liquid combination is not 

 decomposed by sodium carbonate. These very properties afforded later on a satis- 

 factory method for the preparation of the new aldehyde. According to a method 

 given in detail, the authors succeeded in isolating, as they believe, pure cryptal from 

 the oils of Eucalyptus hemiphloia and E. polybractea. However, the constants of both 

 aldehydes do not agree with each other 6 ). 



Cryptal from the oil of E. hemiphloia:— b. p. 99 to 100° (10 mm.), 221° (760 mm.), 

 d 20 o 0.9431, « D — 76.02°, n D2 oo 1.4830; semicarbazone m. p. 176 to 177°; oxime and 

 hydrazone were liquid. 



J ) Comp. Bericht 1921, 24. — 2 ) Liebicfs Annalen 362 (1908), 272. — 3 ) Baker and Smith, A Research 

 on the Eucalypts and Their Essential Oils, 2 nd edition 1920, p. 396. — 4 ) Comp. Reports April 1901, 34; October 

 1901, 29. — 8 ) Baker and Smith, A Research on the Eucalypts and Their Essential Oils, 2 nd edition, 1920, p. 383. 

 — *) No explanation is given for this discrepancy. 



3* 



