OF ARTS AND SCIENCES. 



299 



Benzofurfurau derivatives were' first obtained by Fittig and Ebert* 

 from cumariue derivatives, and later Rossingf obtained cumarone 

 from o-aldehydopheuoxyacetic acid. 



A general method for obtaining such compounds has been published 

 by IIantsch,t which consists in heating sodium salts of phenoles with 

 a-chloracetoacetic etlier, e. g. : 



H 



H O 



H 



H 



ONa CI-C-CO2C2H5 H 



+ 

 H HO-C-CH3 jj 



'C-CO2C2H5 



-f NaCl 



H HO-C-CH, 



H H 



Sodium Phenolate. a-Chloracctoacetic Ether. Intermediate Product. 



H 



O 



H 

 H 



H 



C-CO2C2H5 (a) 



+ H2O 



C-CHg ifi) 



Benzofurfuran Derivative. 



While the above method leads to a-methyl /3-carboxylic derivatives, 

 that of Hantsch leads to /3-methyl a-carboxylic derivatives of benzo- 

 furfuran. 



i. e. that under certain conditions of temperature tlie OH group of an acetyl 

 radical is nearer in space to tlie OC2H5 group of a COOC2H5 group, whereas at 

 a higher temperature (200°) the two OH groups of the acetyl radicals are nearer 

 to one another in space, so that either alcohol or water is split off according to 

 the temperature. Knorr also puts forward the above formula for isocarbopyro- 

 tritaric ether, but favors the ketopentamethylene formula because of tlie be- 

 havior of the ether towards alkalies (Ber. d. chem. Ges., XXII. 167). On the 

 other hand, all the oilier reactions of isocarbopyrotritaric ether are best ex- 

 plained by the above lactone formula. It is therefore highly probable that a 

 similar relationship exists in the very puzzling pyrotritaric acid series as has 

 been shown by Feist (Liebig, Ann. Chem., CCL(VII. 253) to exist in the case of 

 dehydracetic acid. — J. U. Nef. 



* Ann. Chem. (Liebig), CCXVI. 170. 



t Ber. d. chem. Ges., XVII. 3000. 



X Ber. d. chem. Ges., XIX. 1292, 2930, XX. 1332. 



