OF ARTS AND SCIENCES. 199 



Action of Bromine and Water. 



Although Maquenne* had shown that the ready formation of 

 methylfurfurol from isodulcite led directly to the conclusion that 

 it must contain its methyl group in the S position, it seemed 

 desirable to establish this point by independent facts. Since pyro- 

 mucic acid could readily be oxidized by bromine in aqueous solu- 

 tion, and converted into well marked bodies of the maleic acid 

 group, it seemed probable that methylpyromucic acid would also 

 yield analogous products. It was soon found that homogeneous 

 products could not easily be obtained by using an excess of bro- 

 mine, as is the case with pyromucic acid. Although a crystalline 

 derivative could be obtained under certain conditions, the yield 

 was not satisfactory, and viscous products were also formed. With 

 two molecules of bromine, however, it was easy to reach definite 

 results. Limpricht t showed in 1873 that pyromucic acid could 

 be converted into a body which he called the half-aldehyde of 

 fumaric acid by the action of two molecules of bromine upon 

 its aqueous solution, and v. Baeyer % subsequently proved that 

 fumaric acid could be formed from this by the action of argentic 

 oxide. It was evident, if methylpyromucic acid was decomposed 

 in an analogous fashion, that there should be formed either an 

 homologous aldehyde acid, or a ketone acid, according to the posi- 

 tion of the methyl group in the furfuran ring. The formation of 

 a ketone aldehyde under these conditions did not seem possible, 

 since Hill and Sanger § had shown that the aldehj-de group in 

 analogous reactions is invariably formed from the 8 carbon of the 

 pyromucic acid. The product formed from methylpyromucic acid 

 under these conditions proved to be a ketone acid, and a brief 

 description of the results of a preliminary examination which was 

 undertaken at the time by Mr. W. S. Hendrixson || and one of 

 us was published elsewhere about two years ago. For the sake of 

 completeness an account of these preliminary experiments will be 

 included in the description of our own work, and we also owe 

 to Mr. Hendrixson the analytical data which we publish. If 

 methylpyromucic acid is suspended in about fifteen times its 



* Comptes Rendus, CIX. 603. 



t Ann. der Chem. u. Pharm., CLXV. 285. 



X Berichte der deutsch. chem. Gesellsch., X. 1362. 



§ These Proceedings, XXI. 185. 



|| Berichte der deutsch. chem. Gesellsch., XXIII. 452. 



