— 208 — 



Perkin and Wallach *), in their paper on ^-acetyl cyclopentene 

 as the oxidation-product of zl 1 -cyclohexene acetic acid, laid stress upon 

 the fact that the forming of an unsaturated pentacyclic compound was 

 entirely unexpected and surprising, and that this showed how careful 

 an investigator must be in drawing conclusions as to the constitution from 

 oxidative decomposition with permanganate of potassium. Bouveault 2 ) 

 raises a few objections to this conclusion. In the first place he is 

 of opinion that the formation of a cyclopentene derivative from a 

 cyclohexene derivative, caused by the action of an alkaline solution 

 of permanganate, cannot be regarded as in any way surprising, as a 

 reaction producing reverse result has long been known, viz., the 

 conversion of W0 - lauronolic acid into /w-lauronic acid and that of 

 /?-campholenic acid into the zsophoxone of camphor. 



CH 3 CH 3 CH 3 CH. 



\/ \/ 



hfi/ \-CH 3 HX/ \cb 



'I II — * I I 



H 2 C CC0 2 H H 2 Cv ^CH 



jfrtflauronolic acid C-C0 2 H 



.Zrtflauronic acid 



CH B CH 3 CH S CH, 



V V 



h 2 c/ \c.ch 3 t^c/ \:o 



H 2 C C.CH 2 .C0 2 H H 2 C. ^CH 



/?-Campholenic acid C — CH 3 



/rophorone of camphor 



Secondly, and contrary to the view of Perkin and Wallach, 

 Bouveault regards the application of the oxidation-process by per- 

 manganate for determining of the constitution of bodies as entirely 

 justified in the case of hydrocarbons of the methylcyclohexene type, 

 because Wallach only obtained i per cent, of keto-cyclopentene, while 

 a rich yield had been obtained of the normal product of oxidation. 

 Rearrangement, Bouveault thinks, is only to be expected when negative 

 groups are found adjacent to the double-bond. 



We have already previously reported on 1-pinonic acid 3 ) which 

 has been prepared by us from oil of hyssop, as well as on the deri- 



*) Berl. Berichte 42 (1909), 145; Report April 1909, 137. 



2 ) Ibidem 42 (1909), 1055. 



8 ) Report April 1908, 60; April 1909, 137; Gildemeister and Kohler, Uber 

 das Vorkommen von /?-Pinen und 1-Pinocamphon im Ysopol, und einige Beobach- 

 tungen uber Isomerien in der Pinenreihe. Wallach Jubilee publ., p. 414. Vanden- 

 hoek and Ruprecht, Gottingen 1909. 



