Sorbitol selective oxidation

Examples are found for the selective hydroxylation, dehydrogenation and oxidative removal of side chains of steroids, and for the selective oxidation of sorbitol into L-sorbose in the vitamin C synthesis. 

Dimitratos, N., Porta, R, Prati, L., et al. (2005). Synergetic Effect of Platinum or Palladium on Gold Catalyst in the Selective Oxidation of D-Sorbitol, Catal. Lett., 99, pp. 181-185. 

Hydrogenation reactions, particularly for the manufacture of fine chemicals, prevail in the research of three-phase processes. Examples are hydrogenation of citral (selectivity > 80% [86-88]) and 2-butyne-l,4-diol (conversion > 80% and selectivity > 97% [89]). Eor Pt/ACE the yield to n-sorbitol in hydrogenation of D-glucose exceeded 99.5% [90]. Water denitrification via hydrogenation of nitrites and nitrates was extensively studied using fiber-based catalysts [91-95]. An attempt to use fiber-structured catalysts for wet air oxidation of organics (4-nitrophenol as a model compound) in water was successful. TOC removal up to 90% was achieved [96]. 

Oxidation of lactose and maltose with Au/Ti02 catalysts has been reported to give close to 100% selectivity to lactobionic acid and malto-bionic acid, respectively63 which have potential uses in the pharmaceutical and detergent industries, as well as in food. Studies of the catalytic conversion of glucose by hydrogenation and oxidation to produce sorbitol and gluconic acid respectively have also been reported.64 Sorbitol is also manufactured on a 60 000 tonnes per annum scale. 

IDH) from Candida utilis, also known as sorbitol or polyol dehydrogenase[35, 85. Reduction of the ketone occurs to give the alcohol with (S)-stereochemistry. The corresponding (R)-alcohol was obtained by non-stereoselective reduction of the ketone with NaBH(OAc)3 and the (S)-epimer was selectively removed by IDH-catalyzed oxidation. L-Xylose and 2-deoxy-D-orobino-hexose were synthesized by each of these two processes, respectively. 

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