Peroxides diperoxides

Hydroxyall l Hydroperoxyall l Peroxides. There is evidence that hydroxyalkyl hydroperoxyalkyl peroxides (2, X = OH, Y = OOH) exist in equihbrium with their corresponding carbonyl compounds and other a-oxygen-substituted peroxides. For example, reaction with acyl haUdes yields diperoxyesters. Dilute acid hydrolysis yields the corresponding ketone (44). Reduction with phosphines yields di(hydroxyalkyl) peroxides and dehydration results in formation of cycHc diperoxides (4). 

Thermal decomposition of hydroxyalkyl hydroperoxyalkyl peroxides produces mixtures of starting carbonyl compounds, mono- and dicarboxyHc acids, cycHc diperoxides, carbon dioxide, and water. One specific hydroxyalkyl hydroperoxyalkyl peroxide from cyclohexanone (2, X = OH, Y = OOH) is a soHd that is produced commercially as a free-radical initiator and bleaching agent (see Table 5). On controlled decomposition, it forms 1,12-dodecanedioic acid (150). 

R = cyl), eg, with -nitrobenzoyl chloride. Upon reaction with lead tetraacetate, di(hydroperoxyalkyl) peroxides can also be converted to cycHc diperoxides (4). They are also converted to symmetrical or unsymmetrical cycHc triperoxides (5) in the presence of a second ketone and a catalyst, eg, CuSO -HCl (44,119). 

Cyclic Peroxides. CycHc diperoxides (4) and triperoxides (5) are soHds and the low molecular weight compounds are shock-sensitive and explosive (151). The melting points of some characteristic compounds of this type are given in Table 5. They can be reduced to carbonyl compounds and alcohols with zinc and alkaH, zinc and acetic acid, aluminum amalgam, Grignard reagents, and warm acidified iodides (44,122). They are more difficult to analyze by titration with acidified iodides than the acycHc peroxides and have been sucessfuUy analyzed by gas chromatography (112). 

Acid hydrolysis of peroxides (4) and (5) generates carbonyl compounds (parent ketones or aldehydes) and hydrogen peroxide. Basic hydrolysis of cycHc diperoxides with a-hydrogen (those from aldehydes) yields carboxyHc acids (44) ... 

Most ozonolysis reaction products are postulated to form by the reaction of the 1,3-zwitterion with the extmded carbonyl compound in a 1,3-dipolar cycloaddition reaction to produce stable 1,2,4-trioxanes (ozonides) (17) as shown with itself (dimerization) to form cycHc diperoxides (4) or with protic solvents, such as alcohols, carboxyUc acids, etc, to form a-substituted alkyl hydroperoxides. The latter can form other peroxidic products, depending on reactants, reaction conditions, and solvent. 

By-products include ozonides (17). Other peroxidic products including polymeric peroxides and polymeric ozonides can form, depending on reaction conditions, solvent, and olefin used. A variety of cycHc diperoxides (4) have been obtained by ozonolysis of olefins. Both cis- and... 

When hydrogen peroxide is added to an acid solution of Cr(VI), a deep blue color, iadicating the formation of chromium (VI) oxide diperoxide [35262-77-2] is observed. This compound is metastable and rapidly decomposes to Cr(III) and oxygen at room temperature. The reaction... 

Experimental evidence is available to show that at room temperature diperoxides are formed in polyethylene, whereas polypropylene and polyvinyl chloride generate hydroperoxides. The temperature at which the peroxides decompose and initiate grafting depends on the type of polymer used. 

The assessors experienced an explosion while drying the oxide in ethyl ether. Rather drastic precautions are recommended in handling it [1], A preparation, allowed to stand for a week rather than the day specified, exploded during concentration [2], Amine oxides from the standard preparation are inclined to retain hydrogen peroxide of hydration unless it is destroyed during work-up. The perox-idate (or diperoxidate) of dimethylamine oxide would be expected to be far more dangerous than the oxide itself [3],... 

When dibenzal diperoxide 3 was added, at 200°, to a solution of di-benzanthrone a red chemiluminescence was observed67) this is also seen in the reaction of violanthrone (dibenzanthrone) with alkaline hydrogen peroxide/chlorine. 

Cyclic compounds, unnatural, 24 59 Cyclic cooligomerization, 16 238 Cyclic corrosion tests, 16 218 Cyclic diacyl peroxides, 18 473, 477 Cyclic dimethylsiloxanes, 22 575 Cyclic diperoxides, 18 461 Cyclic diperoxyketals, 18 457 Cyclic disulfides, antimicrobial properties of, 23 713... 

Two forms of acetone peroxides are known to exist a dimer called diacetone diperoxide (DADP) and a trimer called triacetone triperoxide (TATP). Figure 3.4 displays the chemical structures of each. 

Procedures. Chromatographic Purification of Ozonization Products. Ozonization products from ethyl 10-undecenoate and 1-octene were chromatographed on silica gel columns (Baker) and eluted with 15 or 25% ether in petroleum ether (b.p., 30°-60°). Fractions were examined by thin-layer chromatography (TLC) on silica gel G Chroma-gram sheet eluted with 40% ether in petroleum ether. For development of ozonide and peroxide spots, 3% KI in 1% aqueous acetic acid spray was better than iodine. The spots (of iodine) faded, but a permanent record was made by Xerox copying. Color of die spots varied from light brown (ozonide) to purple-brown (hydroperoxide), and the rate of development of this color was related to structure (diperoxide > hydroperoxide > ozonide). 2,4-Dinitrophenylhydrazine spray revealed aldehyde spots and also reacted with ozonides and hydroperoxides. Fractions were evaporated at room temperature or below in a rotary evaporator. 

The peroxidation procedure, which is the least often used of all the irradiation techniques, involves irradiation of the substrate in the presence of air or oxygen. This produces diperoxides and hydroperoxides on the surface of fhe subsfrafe, which are stable, and the substrate can be stored until the combination with a monomer is possible. Monomer, with or without solvent, is then reacted with the activated peroxy trunk polymer in air or under vacuum at elevated temperatures to form the graft copolymer. The advantage of this method is the relatively long shelf life of fhe infermediate peroxy trunk polymers before the final grafting step. ... 

The two products formed in Reactions 16 and 17—i.e., hydroperoxides and diperoxides, respectively—exhibit different properties, and this makes it possible to assign a reaction mechanism to a given peroxidation process if one can establish the nature of the resulting peroxide. Thus, hydroperoxides are usually less stable to heat than diperoxides. 

The concentration of hydroperoxides can often be determined by infrared analysis or by chemical titration. Diperoxides are more difficult to detect experimentally. If both substituents of the peroxide are polymeric radicals, P, the corresponding peroxide POOP can actually be considered as an oxygen bridge between two macromolecules and should therefore behave like a crosslink ... 

Diethylidene Diperoxide Diacetaldehyde Peroxide Acetaldehyde Superoxide or Ethylidene Peroxide (called 3.6-Dimethyl-1.2.4.5-tetroxan or Diathyliden-diperoxyd in Ger),... 

An example of an expl resin formed from urea and formaldehyde is entered in Vol 5, D1337-R under Dimethylene Peroxide Carbamide . In Vol 6, F165-R it is mentioned under Formaldehyde and Derivatives . The information on this expl is updated in Vol 9 under Tetramethylene-Diperoxide Dicarbamide ... 

Acetone peroxides 1 A41—A45 diacetone diperoxide 1 A41—A42 triacetone triperoxide 1 A42—A45... 

Tetraoxymethylene Diperoxide. See under Cyclodioxytrimethylene Peroxide in Vol 3, C594-L... 

Diacetin. See under Acetins A31-R Diacetone Diperoxide. See under Acetone Peroxides A41-R... 

It must be noted here that ketone or aldehyde, diperoxides and peroxide oligomers are obtained in non participating solvents whereas alkoxy or alkyl hydroperoxides result from ozonolysis conducted in participating solvents [13]. 

The decarboxylation of diacyl peroxides was also applied in the synthesis of cydopentadecanone, a compound with a musky odor of interest in the perfume industry (Scheme 2.31) [62].The photolysis of tetraacyl diperoxides 119 led to the extrusion of four molecules of C02 to give 121 in 73% yield. When decarboxylation occurred thermally, the product was obtained in only 41% yield. While the diacyl peroxide containing a keto group (106) was shown to give side products, the ketal-protected diperoxide 120 decarboxylated efficiently to give 122 in 65% yield. 

Fig. 1.14 Molecular structures of triacetone triperoxide (TATP), hexamethylene triperoxide diamine (HMTD), methyl ethyl ketone peroxide (MEKP) and diacetone diperoxide (DADP).

The total yield of diperoxides obtained is usually low. Presumably most of the available zwitterions end up as polymeric peroxides. In the ozonolysis of 7 and 8, for example, the total yield of diperoxides is 17.4%. The diperoxides were obtained in the ratio of 1 1.35 0.78 for 9 10 11 as compared with the statistically predicted ratio of 1 2 1. 

Methyltrioxorhenium (MTO) is an extensively used catalyst for olefin epoxidation1241 and a number of reviews are available on its application.125"281 The complex reacts with hydrogen peroxide to form the mono r 2-peroxo species mpMTO and the diperoxide dpMTO. Both complexes are capable of transferring an oxygen atom to olefins or other substrates, as shown in Scheme 5.1, but the diperoxide species is about five times more reactive than the monoperoxo complex.1171 Care has to be taken that halide impurities are absent from the solvent as these are oxidised much faster than olefins.1171... 

---