Sorbose derivatives

Blockierte L-Sorbose-Derivate konnen am Platinkontakt in hohen Ausbeuten in die entspr. L-xylo-Hexulosonsaure-Derivate iibergefuhrt werden. So erhalt man aus 2,3 4,6-Di-0-isopropyliden-L-sorbose in nahe-zu quantitativer Ausbeute 2,3 4,6-Di-0-isopropyliden-L-xylo-hexuloson-saure Methyl-a-L-sorbosid kann zu Methyl-a-L-xylo-hexulosonsaure... 

Tetramethyl- and pentamethyl-derivatives of D-tagatose have already been mentioned,58141 as well as tritylation147148 studies on L-sorbose derivatives. 

Diflubenzuron urea Diflufenican amide, pyridine Dikegulac-sodium (other) sorbose derivative Dimefuron oxadiazolone, urea Dimepiperate thiocarbamate, piperidine Dimethachlor amide... 

Blocked L-sorbose derivatives can be catalytically oxidized in high yields to the corresponding L-xyZo-hexulosonic acid derivatives, using platinum-on-carbon. From the catalytic oxidation of 2,3 4,6-di-0-isopropylidene-L-sorbose, an almost quantitative jdeld of 2,3 4,6-di-0-isopropylidene-L-a /lo-hexulosonic acid has been reported. Similarly, methyl a-L-sorboside gives a quantitative yield of methyl a-L-xylo-hexulosidonic acid. Attempts to prepare L-xylo-hexulosonic acid from this product result in extensive... 

Preparation of Fructose and Sorbose Derivatives Modified at Position 5... 

Various pyrrolidines were prepared by using the chemoenzymatic approach. Thus, 2R,5S-dihydroxymethyl-3R,4A -dihydroxypyrrolidine (3) was prepared from the L-sorbose derivative 36 (Scheme 6). Thus, periodate oxidation of 2-azido-2-deoxythreitol (34) led to 2-azido-3-hydroxypropanal (35), which was treated with DHAP and FDP aldolase to... 

The rates of reaction of triphenylmethyl chloride with several characteristic compounds are given ( 7) in Table I, which also illustrates the effect of the trityl chloride concentration. For the 8-fold excess, the primary alcoholic group of the galactose derivative reacts 226 times as rapidly as the secondary alcoholic group of the glucose derivative. However, the difference between the primary alcoholic group of the sorbose derivative and the secondary hydroxyl of the glucose derivative is only 34 times. 

Iglesias-Guerra and coworkers, prepared aziridine galactopyranoside derivatives and studied their anticancer activity. Guo et al. presented efficient one-pot synthesis of tigogenin saponin. Tiwari et al used click chemistry to synthesize triazolyl ethisterone glycoconjugates. D Andrea et al. presented stereoselective synthesis of p-D-GlcNAc-(l 4)-D-Glc disaccharide starting from lactose. Martin and coworkers, presented synthesis of L-sorbose derivatives. Authors made a critical review of the spectral data available in literature. 

Py and coworkers presented also a convenient route to 2,2-disubstituted piperidines. This strategy involved a highly selective, stereodivergent nucleophilic addition of vinylmagnesium bromide to L-sorbose-derived nitrone 174 which provided hydrojg lamines 175 and 176 (Scheme 36). Crude products were reduced and the resulting amines 177 and 179 were separated by chromatography. Subsequently, JV-allyl-substituted piperidines 178 and 180 were obtained, and transformed into a series of bicyclic derivatives, for example 182 and 183. 

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