546 



SCIENCE PROGRESS 



CH, 



.^ 



CHj— CMe . CHj 



CO — CHa COjEt 

 [iv] 



-->- 



CH, 



/ \ / \ 

 CO C CO 



\ / \ / 



CHj CH2 



[V] 



CHj— CMe . CHj 



1 I I 



CO — CH — CO 



[VI] 



The bridged ring ketone [vi] is the ketonic form of the bridged 

 ring form of orcinol [vii], and the product of the reaction was 

 found to be identical with ordinary orcinol [viii]. The author 

 represents the dynamic change as follows : 



CMe 



HjC 



OC 



CH2 



CO 



CMe 

 HC/|\CH 



HOC 



COH 



CH 



[vi] 



CH 

 [vii] 



CMe 

 HCp^.CH 



HOC \^ COH 

 CH 



[viii] 



He considers that the synthesis of orcinol from dehydracetic 

 acid [ix] carried out by Collie and Myers {Trans. Ghent. Soc, 

 1893, 63, 124) can be so represented as to give either the usual 

 Kekule formula for orcinol or the bridge ring structure, the 

 reaction consisting in the rupture of the lactone ring of dehydr- 

 acetic acid followed by an internal aldol condensation and 

 loss of carbon dioxide. 



CMe 



/\ 

 O CH 



I I 

 OC CO 



\/ 



CH 



COCH3 



[ix] 



OCMe 



\ 

 H3C CH2 



i I 

 -> OC CO 



\/ 



CH 



I 

 COjH 



[X] 



