26 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Action of Oxidizing Agents. 



We have been unable to obtain any characteristic products by the 

 oxidation of the /3-bromcrotonolactone. On boiling with concentrated 

 nitric acid oxidation takes place, but carbonic dioxide is evolved in 

 abundance, and no other definite products were isolated. When 

 heated with bromine in aqueous solution the addition product is ap- 

 parently formed at first, but on boiling this is soon broken up with the 

 evolution of carbonic dioxide. We also noticed in this case the forma- 

 tion of a small amount of a highly crystalline body which on recrystal- 

 lization from alcohol formed long lustrous prisms. The melting point 

 (54° ), the camphor-like odor, and other physical properties, render it 

 extremely probable that this substance was pentabromethan, but it 

 was insufficient in quantity for analysis. The aqueous solution upon 

 evaporation gave a small viscous residue, from which on long standing 

 a few microscopic rhombic plates separated which appeared to be 

 mucobromic acid. 



o-Bromcrotonolactone. 



Since the yb dibrompyromucic acid is as yet unknown, and the 

 a bromine atom of the a/3-dibromcrotonolactone seems always to be 

 first attacked by reagents, it was necessary to try some new method 

 for the preparation of the a-bromcrotonolactone. It occurred to us 

 that it was by no means impossible that it might be made from brom- 

 maleylbromide, since the chloranhydrides of similar dibasic acids were 

 known in several instances to yield lactones on reduction. We soon 

 found on trial that our conjecture was correct. Hill and Sanger * had 

 already shown that a crystalline body having the formula C 4 HBr 3 0o, 

 and yielding monobrommaleic acid when decomposed by water, could 

 be made from /3S-dibrompyromucic acid by the action of bromine in 

 aqueous solution. This brommaleylbromide we therefore prepared, 

 although we modified slightly the method of preparation in that we 

 dissolved the /3S-dibrompyromucic acid in the requisite amount of a di- 

 lute solution of sodic carbonate, and added to this feebly alkaline so- 

 lution slightly more than two molecules of bromine. We attempted 

 to purify the product by distillation in vacuo, and found that it boiled 

 without noticeable decomposition at 124-125° under a pressure of 

 17 mm. The distillate remained liquid for a long time, and then but 



* These Proceedings, XXI. 166. 



