302 REPORT— 1900 



2. The Relation between Camphor and Camphoric Acid is in 

 reality the simple one expressed by the. scheme 



,CH2 ,COOH 



^CO \COOH 



It has been usual in discussing the relationship between these two 

 substances to dismiss the subject with a few words, but the point requires 

 much more careful consideration and proof than it is usually deemed 

 worthy of, and it cannot be insisted too frequently that in dealing with 

 the mutations of closed-chain compounds, such as the derivatives of cam- 

 phor, such transformations should be regarded from all points of view, 

 especially, as in the present instance, where the evidence derived from the 

 different fields of work cannot be viewed in its entirety until the point is 

 decided beyond all doubt. 



In the case in question, fortunately, there is no doubt whatever that 

 the ordinary view is the correct one, as, besides the various modes in 

 which it is possible to pass from camphor to camphoric acid, which have 

 already been referred to, the relationship has been established by a series 

 of simple changes which render it possible to traverse the ground in the 

 reverse direction. The evidence is as follows : ^ — 



(a) Camphoric Acid readily yields Homocamphoric Acid, 



When camphoric anhydride is treated with sodium amalgam under 

 suitable conditions, it is reduced to a lactone, campholide, as follows : — 



/CO. /CHa. 



C«H, / >0 + 4H=C,H,/ >0 + H20 



^CQ/ \ CO / 



and campholide when heated with potassium cyanide yields cyanocampholic 

 acid, from which homocamphoric acid is easily obtained on hydrolysis. 

 The changes are of the following kind : — • 



/CH„. /CH.,.CN /CH.^.COOH 



\ CO / ^COOH ^COOH. 



Campholide. Cyanocampholic Acid. Homocamphoric Acid. 



(b) Homocamphoric Acid and Camphor are related to ojie another in the 



following luay : 



/CH,,.COOH /CH.2 



CgH, / and C^H, / | 



^COOH \C0 



and the evidence on which this statement is based is twofold. 



a-Cyanocamphor yields Homocamphoric Acid on Hydrolysis.— Cya.no- 

 camphor, a product of the action of cyanogen or cyanogen bromide 



' Haller, Compt. Bend., 122, 446, 



