12 



Art. 3.— T. Shibata : 



CH„-CH-CO-OCH, 



' I 

 C(CH,), 



CH.,-CH- 



+ IMgCH(CH3), -^ 



CH,,-C(CH3)-C0-0CH, 



CH.,— CH 



CKCH,), 



/CH(CH3), 

 -C--OMaI 

 \OCH, 



CH-C(CH3)-CO-OCH3 

 CO-CH(CH,), 



i 

 CH,— C(CH;,)— CO-OCH, 



As is known, a r-ketonic acid, like acetylpropionic acid, is easily 

 converted into an unsaturated lactone by long heating, according 

 to the following scheme: — 



CH,-CO-CH,-CH,-COOH -> CH.: C(OH).CHvCHvCOüH 



CH., : C-CH^-CH, 



'I I ' 



O CO 



-> 



In the formation of camphoric anhydride from the above substance 

 C14H24O3 by the action of potassium permangante and of alcoholic 

 potash, dimethylmethylenecampholide might first be formed, the 

 above o-ketonic ester having gone through a change similar to this 

 change of j'-ketonic acids, whence camphoric anhydride is formed 

 by the splitting of the dimethylmethylene residue: — ■ 



CH,-CH C0Cn(CH3X, CH,-CH C:C(CH;,X. CH,-CH CO 



C(CH3)., 



I 

 CH,-C(CH3)-COOCH3 



-^ 



C(CH3),0 



I I 



CH,-C(CH3)-C0 



-^ 



C(CH,)., O 



I "I 

 CH,-C(CH3)-Cü 



The Action of Magnesium Phenyl Bromide 

 on Dimehtyl 1-Isocamphorale. 



^-Isocamphoric acid was prepared from (^camphoric acid by 

 the method of 0. Aschan (Ber., 1889, 27, 2005). The neutral 

 methyl ester of this acid, hitherto unknown, was prepared by a 



