Grignard Eeagent on Camptoric and Isocamphoric Esters. 9 



action of magnesium methyl iodide on camphoric anhydride. In 



camphohdes, the existence of the following two isomers are 

 possible : 



CH„— CH CE.. CH.,— CH CO 



(I) 



C(CH3)o O , and (II) 



C(CH3), 



CH— C(CHs)— CO « CH,-C(CH3)— CEs 



And, in fact, J. Houben (Ber., 1908, 41, 1580) obtained both of 

 the two isomers of dibenzylcampholide by the action of magnesium 

 benzyl chloride on camphoric anhj'-dride. In the case of dimethyl- 

 campholide,. Komppa's crystalline form and my oily one will 

 probably be found to correspond to these two forms. Kommpa 

 gave formula I to his dimethylcampholide without any remark on 

 this point. I am, however, inclined to believe that my oily 

 substance has formula I, and Kamppa's crystalline one has 

 formula II. 



As will be described hereafter, the action of magnesium 

 phenyl bromide on dimethyl isocamphorate results in the formation 



of methyl diphenyl-oxy-isocampholate, ^«-^n'^CO-bcH ' ^^^^ 

 of the two ester groups remaining untouched. In this case, from 

 the point of view of the steric influence, it is most natural to regard 

 the untouched ester group as one in union with that carbon atom 

 which carries a methyl group with it. In the case of the formation 

 of dialkyl(aryl)campholides, the same theory must also hold true, 

 although the intermediate product, methyl dialkyl(aryl)-oxy- 

 campholate could not be isolated, or in other words, the 

 campholides obtained by the action of Grignard reagents on 

 camphoric esters must have formula I. Again, it is also most 

 probable that in the formation of two isomeric campholides from 



