ORGANIC CHEMISTRY 



547 



Me OH 



\/ 

 C 



/\ 

 HjC CH2 



Me 

 /C>^ 



HjC CH 



X^\ 



.^ 



->- 



OC CO 



\ / 

 CH3 



Me 



COH 



OC CO 



\/ 

 CH, 



/S\ 



^ HaC 



I 

 OC 



CH, 



I 

 CO 



-^ 



CH 



COH 



This suggested mechanism is, however, open to criticism. Ingold 

 assumes that the compound reacts in a keto-form throughout, 

 but as the reaction is brought about by syrupy caustic soda at 

 1 50°, an enolic structure seems more rational. Moreover orcinol 

 is probably a secondary product of the reaction, the first pro- 

 duct being an acid which CoUie and Myers suggest is dihydroxy- 

 phenylacetic acid [xi], which loses carbon dioxide on heating to 

 give orcinol. C . CH, . CO^H 



/\ 

 HC CH 



II I 

 HOC COH 



\ ^ 

 CH 



[xi] # 



One feels that a reaction of this sort is too little understood at pre- 

 sent to be used as evidence one way or other. The author claims 

 that his newsynthesis of orcinol is freefromambiguityof this sort, 

 but the recent researches of Thorpe and his co-w'orkers on the 

 phenomenon of ring-chain isomerism suggest that such isomerism 

 is possible though perhaps unlikely in the case of ethyl3-methyl- 

 cyclobutan-i-one-3-acetate,thestartingmaterialforthes3mthesis. 



The bridged formula as a dynamic isomeride of benzene is 

 apphed to the explanation of many of the characteristic reac- 

 tions of benzenoid compounds, but all these can be similarly 

 explained by the dynamic formula of Collie of which the bridged 

 ring is essentially a phase. 



On the speculative side the application of the Lewis-Lang- 

 muir theory to the structure of benzene is exciting considerable 

 interest. J. J. Thomson {Phil. Mag., 192 1, 41, 510) suggested 



