Perhydrate

Hydrogen peroxide is used in many applications throughout a wide variety of industries. The principal use areas are shown in Table 9. Most ate based on the oxidizing properties of hydrogen peroxide. Some are derived from substitution, decomposition, or the formation of perhydrates. 

Peroxohydrates are crystalline adducts containing molecular hydrogen peroxide. These are commonly called perhydrates, but this name is better avoided because historically implied the maximum oxidation state and hjdrate implies the presence of water, neither of which apply to peroxohydrates. They have also been called hydroperoxidates (92). 

R = H, Me2CH). They are obtained as H202 adducts (perhydrates) containing lattice H202. The perhydrate adducts cleave DNA but the unsolvated compounds do not. 

Salts of aminoalkylidenephosphonic acids form perhydrates with hydrogen peroxide which are durable under storage [137], Another method exists for the preparation of aminoalkylidene phosphorus compounds by conversion of white phosphorus with N-hydroxymethyldialkylamine [138-140], as shown in Eq. (80). 

One of the methods for a-hydroxyperoxide (perhydrate) synthesis consists in the addition of hydrogen peroxide to aldehydes or ketones (Scheme 6) as reported by Ganeshpure and Adam °. In the presence of excess aldehyde, the perhydrate is further converted to... 

The oxidation of sulfides to sulfoxides (1 eq. of oxidant) and sulfones (2 eq. of oxidant) is possible in the absence of a catalyst by employing the perhydrate prepared from hexafluoroacetone or 2-hydroperoxy-l,l,l-trifluoropropan-2-ol as reported by Ganeshpure and Adam (Scheme 99 f°. The reaction is highly chemoselective and sulfoxidation occurs in the presence of double bonds and amine functions, which were not oxidized. With one equivalent of the a-hydroxyhydroperoxide, diphenyl sulfide was selectively transformed to the sulfoxide in quantitative yield and with two equivalents of oxidant the corresponding sulfone was quantitatively obtained. 2-Hydroperoxy-l,l,l-fluoropropan-2-ol as an electrophilic oxidant oxidizes thianthrene-5-oxide almost exclusively to the corresponding cw-disulfoxide, although low conversions were observed (15%) (Scheme 99). Deprotonation of this oxidant with sodium carbonate in methanol leads to a peroxo anion, which is a nucleophilic oxidant and oxidizes thianthrene-5-oxide preferentially to the sulfone. 

Hyperol or Perhydrate. A tradename for the compound of hydrogen peroxide and urea. OC(NH2 )2, H2 02, solid, decomp above 82° (Ref 2). It is claimed to be an advantageous replacement for hydrogen, peroxide in chemical analyses (Ref 1)... 

Other preliminary experiments on alkali lignin included oxidations by barium peroxide and alkali (5, 6), alkali fusion, and alkali fusions in the presence of calcium peroxide, sodium borate perhydrate, and monopersulfate compound. Ether extractives and water extractives were examined, but in all cases too many of the oxidation products obtained were new and unidentifiable, and it was impossible to evaluate the experiments adequately with the available techniques. Vanillic acid appeared to be the chief oxidation product under conditions which did not demethylate further or destroy the aromatic nature of the oxidation products. Some oxidation conditions yielded p-hydroxybenzyl moieties as products, and some gave no trace of these products whatever. More detailed studies of the ether-insoluble, water-soluble components of the several oxidation mixtures were postponed until adequate procedures were developed for analytical isolation and identification. 

Other fusions were made under the same conditions but with the addition of sodium borate perhydrate (duPont Perdox containing 15.5% minimum available oxygen) and monopersulfate compound (duPont Oxone containing 4.5% available oxygen). Again, no marked change over the standard fusions was noted. 

It should be noted that the related imine-oxaziridine couple E-F finds application in asymmetric sulfoxidation, which is discussed in Section 10.3. Similarly, chiral oxoammonium ions G enable catalytic stereoselective oxidation of alcohols and thus, e.g., kinetic resolution of racemates. Processes of this type are discussed in Section 10.4. Whereas perhydrates, e.g. of fluorinated ketones, have several applications in oxidation catalysis [5], e.g. for the preparation of epoxides from olefins, it seems that no application of chiral perhydrates in asymmetric synthesis has yet been found. Metal-free oxidation catalysis - achiral or chiral - has, nevertheless, become a very potent method in organic synthesis, and the field is developing rapidly [6]. 

The world capacity for sodium carbonate perhydrate is about 20% of that of sodium perborate, both products being alternately produced in some plants. About 40% of the hydrogen peroxide production of Western Europe is utilized in the production of sodium perborate and sodium carbonate perhydrate. 

Table 1.3-3. Sodium Carbonate Perhydrate consumption in 1991 (estimated) in 10 t.

In contrast with sodium perborate, which is a genuine peroxo compound. Sodium percarbonate is only a perhydrate. It has the composition Na2C03 I.5H2O2. It can be manufactured using dry and wet processes. In a modern dry process, hydrogen peroxide and a sodium carbonate solution are sprayed onto a fluidized bed of sodium percarbonate which is fluidized with warm air. The lines are returned to the process and the oversized particles are ground. 

Hydrogen Peroxide, Sodium Perborate and Sodium Carbonate Perhydrate... 

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