Carbohydrate transformations oxidation

One important application is in the field of carbohydrate transformations, the catalytic oxidation of D-glucose to D-gluconic acid represents an economically competitive route with respect to biochemical oxidation [4], This new process is the result of extensive studies on the selective Cl-hydroxyl group oxidation in the presence of O2 using a Pt or Pd catalyst modified with cocatalysts [5]. 

In spite of the abundant literature dealing with carbohydrate transformations, there is relatively little on lower polyols [6]. In the case of glycerol particular attention has been paid to the influence of cocatalysts, like Bi, on the selectivity of Pd and Pt catalysts, which changes the hydroxyl group oxidation from primary to secondary producit dihydroxyacetone with 70 -80% selectivity [7]. 

This reaction has been used to convert primary and secondary alcohols into corresponding aldehydes and ketones, especially for the sterically hindered alcohols. This reaction has been commonly used in carbohydrate transformation. However, for the oxidation of phenols with DMSO/AC2O, the thiomethoxymethylation of the corresponding phenols occurs." ... 

Abstract This is one of the most important classes of oxidation effected by Ru complexes, particnlarly by RnO, [RuO ] , [RnO ] and RuCljCPPhj), though in fact most Ru oxidants effect these transformations. The chapter covers oxidation of primary alcohols to aldehydes (section 2.1), and to carboxylic acids (2.2), and of secondary alcohols to ketones (2.3). Oxidation of primary and secondary alcohol functionalities in carbohydrates (sugars) is dealt with in section 2.4, then oxidation of diols and polyols to lactones and acids (2.5). Finally there is a short section on miscellaneous alcohol oxidations in section 2.6. 

Two approaches, based on furan, have found wide application in carbohydrate synthesis. Cycloaddition reactions of furan with 2-substituted acrylonitrile or acrolein lead to oxabicycloheptanes which, in tnm, can be transformed to monosaccharides. On the other hand, furfuryl alcohols can be converted—either by the Clauson-Kaas reaction or by mild oxidation—into 5,6-dihydro-4-pyrones, suitable for easy functionalization to sugars. 

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