178 OXYPYROTARTARIC ACID. 



"When treated with caustic potassa, it is resolved into 

 acetic and malic acids and alcohol. 



3. Oxypyrotartaricacid,WH*&= C 3 H 5 (OH)| QQ OH 



Is formed when dicyanhydrine (p. 170) is boiled with 

 caustic potassa. Colorless crystals, easily soluble in 

 water, alcohol, and ether. Fusing point, 135. 

 The following acids are isomeric with this : 



Itamalic acid, C 5 H 8 5 , is produced by heating ita- 

 monochlorpyrotartaric acid (p. 163) with water or 

 carbonates. Long, white needles. Deliquescent, easily 

 soluble in alcohol and ether. Fusing point, 60-65. 

 By heating, it is resolved into water, itaconic acid, and 

 citraconic anhydride. 



Citramalic acid, C 5 H 8 5 . Citraconic acid combines 

 directly with hypochlorous acid, forming chlorcitra- 

 malicacid C 5 H 7 C10 5 , a solid amorphous substance which, 

 when heated with zinc in an aqueous solution, is con- 

 verted into citramalic acid. Chlorcitramalic acid is 

 also formed by the action of chlorine on citraconic 

 acid. Amorphous deliquescent mass. 



Mesamalic acid, C 5 H 8 5 . Is obtained from mesamo- 

 nochlorpyrotartaric acid, like itamalic acid. Deliques- 

 cent mass, that fuses at about 60. 



Glutaric acid, C 5 H 8 5 . Is produced by the action of 

 nitrous acid on amidopyrotartaric acid (p. 163). 

 Syrupy mass, difficultly crystallizable. 



4. Adipomalic acid, C 6 H 10 5 . From monobromadipic 

 acid by decomposing it with potassa-ley. Easily solu- 

 ble, sticky, gradually crystallizing mass. 



