2.3.4.5- Tetrahydroxy-pentanoic acid

OSO4 catalyses the oxidation of furosemide (Fur) by alkaline diperiodatoargentate(in) (DPA) to 2-(4-carboxy-2-oxo-but-3-enylamino)-4-chloro-5-sulfonyl-benzoic acid the reaction order in Fur is less than unity and the rate increases with OH and decreases with 104 ions. The reactive oxidant and catalyst species are [Ag(H2l06)(H20)2] and [0s04(0H)2] , respectively.In the similar oxidation of xylitol (Xyl) to 2,3,4,5-tetrahydroxy-pentanoic acid, the reaction has an order less than unity in Xyl and OH ions, and a negative fractional order in IO4" ion. " [Ag(H2l06) (1120)2] is the reactive species in the similar un-catalysed oxidation for which the order is less than unity in Xyl and the rate increases with OH but decreases with 104 ions. ... 

However, the amine-bearing stereogenic center could advantageously be generated from an alcohol function in a suitable precursor. Since this would likely involve an inversion of the configuration, the tetrahydroxy-pentanoic acid shown in Scheme 13.18 would be an attractive intermediate. Perusal of the list of sugar structures shown in Schemes 4.5 and 4.6 identifies L-arabinose as a readily available starting point [13]. 

Pentanoic acid, 2,3,4,5-tetrahydroxy-HOCHz-(CHOH)3-COOH 926, 4249 ... 

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