Notes on scientific research. 149 



The substance gave a violet coloration when ferric chloride was added to its 

 alcoholic solution, and exhibited mutarotation to a slight extent only, and that in 

 an opposite sense to the mutarotation of the corresponding camphor derivative 

 (Wd °f a freshly prepared benzenic solution rose from — 125.5° to — 130.5° after 

 24 hours). Benzoyloxymethylene-epicamphor melted at 106°; aminomethylene-Z-epi- 

 camphor, m. p. 122°, was obtained by heating hydroxymethylene-epicamphor with 

 aqueous ammonia; it does not exhibit mutarotation, contrary to the corresponding 

 camphor derivative. Anilinomethylene-Z-epicamphor, m. p. 101°, no mutarotation; 

 /?-naphthylaminomethylene-£-epicamphor, m. p. 109 to 110°, slight mutarotation. 



By heating I- or tf-epicamphoroxime with sulphuric acid of 20 per cent, the authors 

 obtained /-epicampholenonitrile (b. p. 145° [100 mm.], [«] D — 27.4°, passing over by 

 hydrolysis into /-a-epicampholenic acid, b. p. 166° (30 mm.), [«] D — 38.4° and d-epi- 

 campholenonitrile (b. p. 146 to 147° [100 mm.], [«] D + 26.2°; d-epicampholenic acid, 

 b. p. 164 to 165° [30 mm.], [«] D + 39.2°). 



Attempts to prepare ^-epicampholenonitrile and its derivatives under the identical 

 conditions as for obtaining /2-campholenic derivatives 1 ), were unsuccessful. 



On reduction, /-epicampholenonitril is converted into Z-epicamphylamine, b. p. 128° 

 (100 mm.). 



When £-epicampholenic acid is oxidised with potassium permanganate, the main 

 product formed is a mixture of syrupy acids from which a ketonic acid (semicarbazone, 

 m. p. 203°) could be isolated. In addition, there is formed the lactone of hydroxy- 

 ketodihydroepicampholenic acid (II), m, p. 80°; [a] D + 45.8°. On oxidising the syrupy 

 acids from the permanganate oxidation with chromic acid, an optically active, monobasic 

 acid, (semicarbazone, m. p. 168°) was obtained. 



Piperitone. — In their paper on the ketone piperitone contained in various eucalyptus 

 oils, H. G. Smith and A R. Penfold 2 ) had arrived at the conclusion that piperitone is 



either zl 4 -menthenone-3 or z^-menthenone-S. L. Givaudan § Co. 3 ) CH 3 



were able to prove that the properties of the ketone — except in I 



its rotatory power — answered to the zl^menthenone-S prepared /^ 



originally by Wallach 4 ) from a trihydroxyterpane m. p. 120° sub- H 2 C,/ ^CH 



sequently found by us 5 ) in Japanese peppermint oil and by Roberts 6 ) | 



in the oil of Cymbopogon sennaarensis. Hence, Givaudan $ Co. regard 2 \ / 



piperitone as identical with zP-menthenone-S. We wish to add that, CH 



although this conclusion does not seem to be fully proved, yet X.. 



piperitone appears to be a d 3 -menthenone. The reason for our opinion H 3 C/ ^CHs 



has been given in our preceding Bericht (Germ, ed.) p. 24, footnote. ^-Menthenone-S. 



W. D. Cohen 7 ) tested various alcohols as to their power of reducing benzophenone 

 when exposed to sun-light. In all cases, whenever a reaction took place, benzopinacone 

 was produced. The presence of water retarded the reaction. The reducing action was: — 

 with methyl alcohol, 100 per cent, cydohexanol, above 90 per cent., benzyl alcohol 

 about 80 per cent., geraniol about 17 per cent., citronellol and cinnamyl alcohol per cent. 

 of the ketone. The alcohols were transformed respectively into formaldehyde; cyclo- 

 hexanone; triphenylglycol, resin, a little benzaldehyde; citral. 



This reduction of aromatic ketones is a photochemical process and hence the 

 reaction-velocity independent of the concentration of the benzophenone. The oxidation 



x ) Cf. BerU Her. 30 (1897), 243, 405. — 2 ) Cf. Bericht (Germ, ed.) 1921, 24. — 3 ) Perfum. Record 12 

 (1921), 80. — *) Lielig's Anncden 362 (1908), 271. — 5 ) Report October 1910, 97. — ?) Cf. Report 1916, 18. 

 '■) Bee. tro.r. chim. Foys-Bas 39 (1921), 243. As per Chem,. Zentralbl. 1921, III. 785. 



