298 



PROCEEDINGS OF THE AMERICAN ACADEMY 



The furfuran derivative is unquestionably formed according to the 

 following equation : — 



CI 



CI 



o 



CI 

 HO 



-OH HO-C-CH3 CI 

 C-CO2C0H5 HO 



C-CH3 



IC-CO2C2H5 



+ H/i 



CI 



CI 



TricMorhydroquinoneacetoacetic Ether. 



Benzofurfuraa Derivative. 



That acetoacetic ether is not a ketone, but a phenol-like body (^-oxy- 

 crotonic ether), has been made highly probable by the work ot" Nef, 

 soon to api^ear in Liebig's Annalen. In order, therefore, to explain 

 the above reaction, the assumption of a pseudo or mobile modification 

 of trichlorhydroquinoneacetoacetic ether is unnecessary ; and the ease 

 with which this anhydride formation takes place depends entirely oii 

 the position of the atoms in space.* 



* In some cases only the anli3'dricle can be obtained (see Ann. Chem. Lie- 

 big). In this connection I would lilce to point out, that diacetylsuccinic ether, 



CH3 CH3 



I I 



COH HOC 



HgC.O.C-C- 



-C-C0.,C,H5, 



according to Knorr, splits off on heating either water (200°), forming the fur- 

 furan derivative, 



H3C— C C— CH3 



II II 



H5C2O2C-C C-C O2 C^ H5, 



(Ber. d. chem. Ges., XVII. 2863), or alcohol (170°), forming isocarbopyrotritaric 

 etiier (Ber. d. cliein. Ges., XXK. 159). Knorr thinks it probable that the latter 

 substance is a ketopentamethylene derivative, just as Fittig (Ber. d. chem. Ges., 

 XVIII. 3410) regards pyrotritaric ether as a ketopentamethylene derivative. 

 It is however far more probable that the splitting off of alcohol from diacetjl- 

 succinic ether takes place as follows : 



H,C-C-OH C.,H,0-CO 



H,C,0.,C-C- 



*5'-'2'-'2 



Diacetylsuccinic Etber. 



-C=COH-CHo 



H3C-C 



H5C..O0C-C- 



/0\ 



CO 



I 



-C=rCOH-CH, 



+C,H50H 



Isocarbopyrotritaric Ether. 



