With sodium periodate

Diaryl tellurium compounds were oxidized to diaryl tellurium oxides by sodium periodate in a refluxing mixture of acetonitrile/methanol/water.  

Bis[3-metfaoxyphenyl] Tellurium Oxide 0.80 g (2.3 mmol) of bis[3-methoxyphenyl] tellurium and 0.50 g (2.3 mmol) of sodium periodate are added to 30 ml of acetonitrile/methanol/water (1/1/1, v/v/v) and the mixture is heated under reflux for 2 h. The mixture is allowed to cool, 100 ml of water are added, and the mixture is extracted 3 times with 30 ml of chloroform. The combined extracts are evaporated, the residue is chromatographed on silica gel with chloroform/methanol (9/1, v/v) as the mobile phase. The eluate is evaporated and the residue is reerystalUzed from benzene yield 0.26 g (22%) m.p. 189-191°. According to elemental analyses, the product contains two molecules of water and 1.5 molecules of benzene per molecule of tellurium oxide. 

6-trimethylphenyl] tellurium oxide (m.p. 180°) was similarly prepared in 95% yield.  

Phenyl cycloalkyl tellurium compounds were also oxidized by sodium periodate in aqueous methanol to the corresponding tellurium oxides. These compounds are unstable at 20° and eliminate benzenetellurenic acid with formation of cycloalkenes and ring-contracted cycloalkyl aldehydes.  

Diorgano telluriums were oxidized by chloramine-T, AT-chlorosuccinimide, and N-bromosuccinimide Hydrolysis of the oxidation products produced diorgano tellurium oxides. 

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Chemical degradation studies carried out on streptovaricias A and C, which are the primary components of the cmde complex, yielded substances shown ia Figure 1. Streptovaricia A (4), consumes two moles of sodium periodate to yield variciaal A [21913-68-8] (1), 0 2 200, which accounts for the ahphatic portion of the molecule, and prestreptovarone [58074-37-6] (2), C2C)H2C)N02, which accounts for the aromatic chromophore of the streptovaricias (Fig. 2). Streptovaricia G (9) is the only other streptovaricia that yields prestreptovaroae upoa treatmeat with sodium periodate. Treatmeat of streptovaricias A (4), B (5), C (6), E (8), and G (9) with sodium periodate and osmium tetroxide yields streptovarone [36108-44-8] (3), C24H23NO2, which is also produced by the reaction of prestreptovarone with sodium periodate and osmium tetroxide (4,65). A number of aliphatic products were isolated from the oxidation of streptovaricia C and its derivatives (66). 

Only sulfoxidation, and no elimination, occurs when the hydrochloride of 2 (R = Me) is treated with sodium periodate at room temperature.3 Ketone 4, which represents the tautomeric form of dibenzo[6,/]thiepin-10-ol, can be sulfoxidized with hydrogen peroxide at room temperature to provide sulfoxide 5 in 56% yield however, at reflux temperature oxidation occurs additionally at the carbon atom next to the oxo group and sulfone 6 is isolated in 79% yield.3... 

Dihydro-l-benzothiepin 1-oxide (21) is obtained in 77% yield when 19 is treated with sodium periodate in glacial acetic acid at 0 °C, while a second method ultilizing sulfuryl chloride at — 70°C gives the dichlorosulfurane intermediate 20 and ultimately the sulfoxide 21 in 79% yield.86... 

Aziridine-2-carboxylates 12 (Scheme 3.4) have also been prepared from 3-hy-droxy-a-amino esters 9 by treatment with sulfuryl chloride in place of tosyl or mesyl chloride. Treatment of 9 with thionyl chloride in the presence of triethylamine, followed by oxidation of 10 with sodium periodate and a catalytic amount of... 

Osmium tetroxide used in combination with sodium periodate can also effect alkene cleavage.191 Successful oxidative cleavage of double bonds using ruthenium tetroxide and sodium periodate has also been reported.192 In these procedures the osmium or ruthenium can be used in substoichiometric amounts because the periodate reoxidizes the metal to the tetroxide state. Entries 1 to 4 in Scheme 12.18 are examples of these procedures. Entries 5 and 6 show reactions carried out in the course of multistep syntheses. The reaction in Entry 5 followed a 5-exo radical cyclization and served to excise an extraneous carbon. The reaction in Entry 6 followed introduction of the allyl group by enolate alkylation. The aldehyde group in the product was used to introduce an amino group by reductive alkylation (see Section 5.3.1.2). 

Another interesting conversion of a protoberberine to a rhoeadine skeleton was developed by Murugesan et al. (100). The ketol 176 obtained easily from berberine (15) (Section IV,A,2) was oxidized with sodium periodate to the keto lactone 451, which was transformed to the rhoeadine analogs 452 and 453 by known methods (Scheme 91). Their stereochemistry at the anomeric carbon was not fully clarified. 

This same type of modification strategy also can be used to create highly reactive groups from functionalities of rather low reactivity. For instance, carbohydrate chains on glycoproteins can be modified with sodium periodate to transform their rather unreactive hydroxyl groups into highly reactive aldehydes. Similarly, cystine or disulfide residues in proteins can be selectively reduced to form active sulfhydryls, or 5 -phosphate groups of DNA can be transformed to yield modifiable amines. 

Figure 1.106 An N-terminal serine or threonine residue can be oxidized with sodium periodate to produce an aldehyde group. The reaction can be quenched with sodium sulfite to eliminate excess periodate.

Figure 1.108 Glycoproteins that have been treated with sodium periodate to produce aldehyde groups can be further modified with adipic acid dihydrazide to result in a hydrazide derivative.

Dissolve the macromolecule-containing aldehydes to be blocked (i.e., a glycoprotein that has been oxidized with sodium periodate to create formyl groups) at a concentration... 

Figure 4.7 DST may be used to crosslink amine-containing molecules, forming amide bond linkages. The central diol of the cross-bridge is cleavable by treatment with sodium periodate.

The carbonyl-reactive group on these crosslinkers is a hydrazide that can form hydrazone bonds with aldehyde residues. To utilize this functional group with carbohydrate-containing molecules, the sugars first must be mildly oxidized to contain aldehyde groups by treatment with sodium periodate. Oxidation with this compound will cleave adjacent carbon-carbon bonds which possess hydroxyl groups, as are abundant in polysaccharide molecules (Chapter 1, Sections 2 and 4.4). 

Figure 5.13 M2C2H can be used to crosslink a sulfhydryl-containing molecule with an aldehyde-containing compound. Glycoproteins may be conjugated using this reagent after treatment with sodium periodate to form reactive aldehyde groups.

Figure 5.35 ABH reacts with aldehyde-containing compounds through its hydrazide end to form hydrazone linkages. Glycoconjugates may be labeled by this reaction after oxidation with sodium periodate to form aldehyde groups. Subsequent photoactivation with UV light causes transformation of the phenyl azide to a nitrene. The nitrene undergoes rapid ring expansion to a dehydroazepine that can couple to nucleophiles, such as amines.

Figure 8.2 Crosslinkers containing a diol group in their cross-bridge design may be cleaved by oxidation with sodium periodate.

Figure 9.11 This carbohydrazide-containing fluorescein derivative can be used to modify aldehyde-containing molecules. Glycoconjugates may be labeled with this reagent after treatment with sodium periodate to produce aldehydes.

Oxidation of IgG Carbohydrate Residues with Sodium Periodate... 

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