Oxidation with ruthenium tetraoxide

C. Oxidation with Ruthenium Tetraoxide and Chromate Based... 

Synthesis of D-apiose from 1,2-O-isopropylidene- -L-threofuranose (28) has been accomplished.128 Oxidation with ruthenium tetraoxide... 

Uronic acid degradation of the fully methylated Klebsiella type 47 capsular polysaccharide120 results in a partially methylated polysaccharide having a disaccharide repeating-unit (see Section IV,2, p. 218), in which the hydroxyl groups at C-3 in the L-rhamnose residues are free. Oxidation with ruthenium tetraoxide consequently gave the product 82, which, on treatment with base, followed by... 

Isopropylidene-/ -D-fhra>-pentofuranosyl-2-ulose)adenine (22) was obtained38 from 9-(3,5-0-isopropylidene-/ -D-xylofuranosyl) adenine (21) by oxidation with ruthenium tetraoxide.37... 

The hetero Diels-Alder reaction (909 —> 910) produces a 5 1 mixture of diastereomers from which cis-910 is isolated by flash chromatography (95% optically pure). Reduction of the ketone carbonyl followed by methanolysis furnishes the axial glycoside 911. The furan heterocycle behaves as a masked carboxylic acid function that can be liberated by oxidation with ruthenium tetraoxide. The conversion of 911 to 912 requires 13 steps. 

Oxidation of l,2 5,6-di-0-isopropylidene-a-D-glucofuranose (217) with ruthenium tetraoxide, using a phase-transfer catalyst, gave the 3-ulose derivative 218, which by further hydrolysis afforded D-n Zw-hexos-3-ulose 219. Benzyltriethylammonium chloride (BTEAC) was used as the catalyst. Using the same oxidant and conveniently derivatized starting materials, a-D-xy/o-hexofuranos-5-ulose, a-D-n Zw-hexofuranos-5-ulose, and /f-L-arabino-hexofuranos-5-ulose derivatives were obtained.436... 

Oxidation of dianhydrohexopyranoses with ruthenium tetraoxide yields all four possible keto-epoxides469 these can be readily transformed into the 3-deoxy ketones459 (see Sect. VII,3,b). The same agent oxidizes l,6-anhydro-2,3-di-0-benzoyl-/3-D-glucopyranose52 (89). The selectivity of the lithium aluminum deuteride reduction of the glycos-... 

First example for the oxidation of cyclic amines with ruthenium tetraoxide Sheehan and Tulis [136], Yoshifuji et al. [137, 138], Tanaka et al. 139]. 

Epimerization of 50 at C-3 furnished carba-a-DL-allopyranose (60). Stepwise, 0-isopropylidenation of 50 with 2,2-dimethoxypropane afforded compound 56. Ruthenium tetraoxide oxidation of 56 gave the 3-oxo derivative 57, and catalytic hydrogenation over Raney nickel converted 57 into the 3-epimer 58 exclusively. Hydrolysis of 58, and acetylation, provided the pentaacetate 59, which was converted into 60 on hydrolysis. ... 

Ruthenium tetraoxide is a powerful oxidant it is more reactive than osmium tetraoxide, and combines explosively with ether or benzene, so that it is generally used as a dilute solution in carbon tetrachloride. Beynon et al.155 first demonstrated the usefulness of this reagent in carbohydrate chemistry by converting methyl 4,6-0-benzylidene-2-deoxy-a-D-n bo- and -D-uraZu rao-hexopyranosides into methyl 4,6-0-benzylidene-2-deoxy-a-D-eryt/zro-hexopyranosid-3-ulose. 

The oxidation catalyst is believed to be ruthenium tetraoxide based on work by Engle,149 who showed that alkenes could be cleaved with stoichiometric amounts of ruthenium tetraoxide. Suitable solvents for the Ru/peracid systems are water and hexane, the alkene (if liquid) and aromatic compounds. Complex-ing solvents like dimethylformamide, acetonitrile and ethers, and the addition of nitrogen-complexing agents decrease the catalytic system s activity. It has also been found that the system has to be carefully buffered otherwise the yield of the resulting carboxylic acid drops drastically.150 The influence of various ruthenium compounds has also been studied, and generally most simple and complex ruthenium salts are active. The two exceptions are Ru-red and Ru-metal, which are both inferior to the others. Ruthenium to olefin molar ratios as low as 1/20000 will afford excellent cleavage yields (> 70%). vic-Diols are also... 

Overend and coworkers have employed ruthenium tetraoxide in carbon tetrachloride for the oxidation of single hydroxyl groups in acetals of methyl glycosides. Similar oxidations may be performed in the presence of sulfonic ester groups, the oxidant being continuously regenerated with potassium metaperiodate. 

BENSULFOID (7704-34-9) Combustible solid (flash point 405°F/207°C). Finely divided dry materia forms explosive mixture with air. The vapor reacts violently with lithium carbide. Reacts violently with many substances, including strong oxidizers, aluminum powders, boron, bromine pentafluoride, bromine trifluoride, calcium hypochlorite, carbides, cesium, chlorates, chlorine dioxide, chlorine trifluoride, chromic acid, chromyl chloride, dichlorine oxide, diethylzinc, fluorine, halogen compounds, hexalithium disilicide, lampblack, lead chlorite, lead dioxide, lithium, powdered nickel, nickel catalysis, red phosphorus, phosphorus trioxide, potassium, potassium chlorite, potassium iodate, potassium peroxoferrate, rubidium acetylide, ruthenium tetraoxide, sodium, sodium chlorite, sodium peroxide, tin, uranium, zinc, zinc(II) nitrate, hexahydrate. Forms heat-, friction-, impact-, and shock-sensitive explosive or pyrophoric mixtures with ammonia, ammonium nitrate, barium bromate, bromates, calcium carbide, charcoal, hydrocarbons, iodates, iodine pentafluoride, iodine penloxide, iron, lead chromate, mercurous oxide, mercury nitrate, mercury oxide, nitryl fluoride, nitrogen dioxide, inorganic perchlorates, potassium bromate, potassium nitride, potassium perchlorate, silver nitrate, sodium hydride, sulfur dichloride. Incompatible with barium carbide, calcium, calcium carbide, calcium phosphide, chromates, chromic acid, chromic... 

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