Leuconic acid

The researches of Hantsch (Ber. xx.) make it improbable that the absence of colour in triquinoyl and leuconic acid is due to hydration. 

Eurhodines are also formed by the action of triamidobenzene on /S-naphthoquinone, glyoxal, benzil, isatine, and leuconic acid. 

The constitution of the above substances was first elucidated by R. Nietzki and Th. Benckiser. They converted nitranilic acid ( -dinitrodihydroxyquinone), C (N02)2(0H)202, into hexahydroxybenzene, C3(OH)e(I), which was identical with Lerch s trihydrocarboxylic acid, hence the black potassium carboxide (COK)n is not CjoKioOio but Ce(OK)e, derived from hexahydroxybenzene (I). Rhodizonic acid they found was dihydroxydiquinoyl (II), C6(0H)204, identical with Lerch s carboxylic acid. Leuconic acid is C5(OH)io, formulated as III. 

Leuconic Acid (Pentaketopentamethylene, pentaketocydopentane, cydopentane-pentone)... 

This is easily oxidised to dihydrocarboxylic acid CjoHsOio hydrocarboxylic acid CioH Oio, carboxylic acid C10H4O10, and croconic acid CgHgOg. Hie first three compounds are oxidised by nitric acid to oxy-carboxylic acid , CioHsgOgg. By the oxidation of croconic acid with nitric add. Will and Lerch obtained a colourless crystalline acid, which Will called leuconic add and Lerch oxycroconic acid, but the supposed sdts were really decomposition products. They found the formula CgOg + sHjO for leuconic add. 

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