Oxidations sodium periodate

In summary, the reaction of osmium tetroxide with alkenes is a reliable and selective transformation. Chiral diamines and cinchona alkakoid are most frequently used as chiral auxiliaries. Complexes derived from osmium tetroxide with diamines do not undergo catalytic turnover, whereas dihydroquinidine and dihydroquinine derivatives have been found to be very effective catalysts for the oxidation of a variety of alkenes. OsC>4 can be used catalytically in the presence of a secondary oxygen donor (e.g., H202, TBHP, A -methylmorpholine-/V-oxide, sodium periodate, 02, sodium hypochlorite, potassium ferricyanide). Furthermore, a remarkable rate enhancement occurs with the addition of a nucleophilic ligand such as pyridine or a tertiary amine. Table 4-11 lists the preferred chiral ligands for the dihydroxylation of a variety of olefins.61 Table 4-12 lists the recommended ligands for each class of olefins. 

Ruthenium(IV) oxide-Sodium periodate, 268 Ruthenium tetroxide, 268 Tetrachlorotris [ bis (1,4-diphenylphos-phine)butane]diruthenium, 288 Tetrakis(trifluoroacetate)ruthenium, 289... 

Photooxygenation of alkylidenecycloproparenes provided a complex mixture of cleavage products derived from an intermediate dioxetane. From 1,1-diphenylmethylenebenzocyclopropene, a spirophenanthrone 18 was isolated in 13% yield.Osmium(VIII) oxide/sodium periodate resulted in a mixture of cleavage and ring-expansion products. 

Overall, ozone compares favorably with other approaches for oxidative alkene cleavage involving Osmium Tetroxide, Potassium Permanganate, Ruthenium(VIII) Oxide, Sodium Periodate, or chromyl carboxylates which are costly, toxic, involve metal wastes, and may require detailed workup procedures. 

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). 

A second method uses sodium periodate (NaI04) as the oxidant in the presence of the readily available protein bovine serum albumin. In this procedure, the sulfide is complexed in the chiral envirorunent of the protein. Although the oxidant is achiral, it encounters the sulfide in a chiral envirorunent in which the two faces of the sulfide are differentiated. 

Alicyclic hydroxamic acids undergo several specific oxidative cleavage reactions which may be of diagnostic or preparative value. In the pyrrolidine series compounds of type 66 have been oxidized with sodium hypobromite or with periodates to give y-nitroso acids (113). Ozonolysis gives the corresponding y-nitro acids. The related cyclic aldonitrone.s are also oxidized by periodate to nitroso acids, presumably via the hydroxamic acids.This periodate fission was used in the complex degradation of J -nitrones derived from aconitine. 

Chloro-2-(3-methyl-4H-1,2,4-triazol-4-yDbenzophenone (Oxidation of 7solution prepared by adding sodium periodate (2 g) to a stirred suspension of ruthenium dioxide (200 mg) in water (35 ml). The mixture became dark. Additional sodium periodate 18 g) was added during the next 15 minutes. The ice-bath was removed and the mixture was stirred for 45 minutes. Additional sodium periodate (4 g) was added and the mixture was stirred at ambient temperature for 18 hours and filtered. The solid was washed with acetone and the combined filtrate was concentrated in vacuo. The residue was suspended in water and extracted with methylene chloride. The extract was dried over anhydrous potassium carbonate and concentrated. The residue was chromatographed on silica... 

To reduce the effects of corrosion, inhibitors are added, typically sodium chromate in the salt brines and sodium phosphate in the glycols. These are alkaline salts and help to counteract the effects of oxidation, but periodic checks should be taken, and borax or similar alkali added if the pH value falls below 7.0 or 7.5 [1]. 

The Cg-amine, originally obtained by the methanolysis of kasugamycin, on treatment with lead tetraacetate or sodium periodate afforded a nitrile amine, with evolution of carbon dioxide, showing a maximum at 2200 cm.-1. This reaction is explained only by the structure (13). The -N-C=N group of the product can be formed by oxidative decarboxylation and can be easily rationalized by the present understanding of such reagents (2, 13) as shown below. On the other hand, the treatment... 

Periodate Oxidation of C9-Amine (3). C9-Amine hydrochloride (268 mg., 1 mmole) was treated with a solution of sodium periodate (235 mg.,... 

We examined the reaction of triose reductone with both periodate and iodate (55,56), and found that, whereas iodine was invariably set free from both sodium periodate and sodium iodate if the concentration of the reductone were greater than 10 3M, no iodine was liberated at lower concentrations (e.g. 6 x 10 4M) of substrate, even in the presence of relatively large amounts of the oxidants. 

The oxidation of diethyl 3,6-hexanooxepin-4,5-dicarboxylate with a mixture of sodium periodate and potassium permanganate as oxidizing agent gives diethyl 3-[(formyioxy)methylene]-l 0-oxocyclodec-l-en-l,2-dicarboxylate (2) in 91 % yield.130 A minor modification of the reaction conditions gives two products 2 (35 %) and a product which retains the oxepin structure (23 %) identified as the same lactone described in Section 1.2.1.1.129... 

When the hexamethylene bridge already contains a ketone function, the corresponding cyclo-decenedione derivative 3 is obtained upon regioselective oxidation of the C-C double bond a with potassium permanganate and sodium periodate.38... 

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