Thronic acid

Syntheses of some pentonohydroxamic acid derivatives are covered in Chapter 10. Alkaline degradation of 5-O-a-D-glucopyranosyl-D-fructopyranose (leucrose) has afforded two novel saccharinic acids, 2-C-(2-hydroxyethyl)eiy-thronic acid and 2-C-(2-hydroxyethyl)threonic acid. Treatment of 4,6-O-ethyl-idene-D-glucose with the sulfur ylid JNr,iST-diethyl trimethylsulfonium-acetamide gave the epoxyaldonamide 6 as well as stereoisomers. ... 

Liq. Very sol. H.O, EtOH. Exliibits rnuta rotation. [a]o +21-5° (equilibrium value in HgO). Reduces Fehling s in the cold. Ox. —> Z-ery-thronic add — mesotartaiic acid. NaHg — meso-erythritd. Hot Hd —> lactic acid. Phloroglucinol —-> red. col. 

The presently known chromophores are 4-hydroxy-cinnamic acid (e.g., in Ectothiorhodospira halophila, now reclassified as Halorhodospira halophila see Chapter 123), carotenoids (e.g., retinal in Halobacterium salinarum, see Chapter 124), pterins and flavins (e.g., in Euglena gracilis, see Chapter 115), and dian-thronic molecules (e.g., stentorin in S. coeruleus and blepharismins in B. japonicum, see Chapter 122). 

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See also in sourсe #XX -- [ ]

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