12 . PROCEEDINGS OF THE AMERICAN ACADEMY. 



described by Lieberinan,* Allendorf,f Racine, X and Perkin.§ Muco- 

 bromoxime is so unstable that it passes spontaneously into its anhy- 

 dride, and can be formed only by the actiou of free hydroxylamine in 

 aqueous solution. The anhydride is formed through the hydrochlorate 

 in alcoholic solution, and by boiling this alcoholic solution or by heat 

 alone is converted into dibrommaleiuimide. The oxime or its anhy- 

 dride is further converted into the acid ammonium salt of dibrom- 

 maleic acid by boiling it with water. The ready formation of oximes 

 of perfectly normal character from mucobromic acid would in itself 

 naturally be considered as establishing the aldehyde character of this 

 acid. Still the difficulty in explaining the conversion of the broman- 

 hydride of an aldehyde acid into a lactone by reduction with stannous 

 chloride in the cold is so great that it seems to us more rational to 

 suppose either that hydroxylamine acts directly upon an oxylactone of 

 this type and that the ordinary oxime is then formed by molecular 

 rearrangement, or that under the conditions of the reaction the hydrox- 

 ylamine acts only through the fixation of a molecule of water, and the 

 breaking of the lactone ring with formation of the aldehyde acid. 



In this connection we were interested to know whether the esters 

 of mucobromic acid would enter into reaction as readily as the free 

 acid. While it seemed probable that the ester of the aldehyde acid 

 of the form 



BrC - Cq 



BrC-COOCH 



3 



would be attacked by hydroxylamine quite as readily as the free acid, 

 the ester formed from the oxylactone. 



might well prove more refractory. Several years ago Lieberman || 

 tried the behavior of the ethylester of opianic acid with hydroxylamine, 



* Berichte A. deutsch. chera. Gesellsch., XIX. 2278, 2923. 



t Ibid., XXIV. 3264. 



} Ann. d. Chem. u. Pharm., CCXXXIX. 81. 



§ Journ. Chem. Soc, LVII. 1069. 



|| Berichte d. deutsch. chera. Gesellsch., XIX. 2926. 



