Hydrogen peroxide alkaline

Alkaline Hydrogen Peroxide. ajS-Unsaturated ketones (123) were epoxidized with alkaline hydrogen peroxide to form 4/5,5/ -epoxyandrostane-6,17-diones (124). The presence of a 3j -hydroxy-group was found to be advantageous during epoxidation. Initial attempts to epoxidize zerumbone (125) 

Metal-catalysed Epoxidation. Many of the reports of metal-catalysed formation of epoxides are associated with the development of more economic and efficient industrial routes to simple epoxides. A review has appeared on the manufacturing processes for production of ethylene oxide by direct gas-phase oxidation of olefins. Further reports on this process include the rather unusual use of potassium chloride and quartz catalysts. The more usual silver-catalysed epoxidation of ethylene has been studied in detail both from a kinetic and from a stereochemical point of view. The latter 

The synthesis of styrene oxide from styrene in the presence of oxygen and Ru complexes and the formation of tetramethylethylene oxide from the corresponding olefin in the presence of Rh and Ir complexes can both be explained by free-radical-initiated autoxidation. The hydroperoxides thus formed act, in concert with the metal catalysts, as epoxidizing agents on other olefin molecules. 

Bathory, A. Balogh, and I. Hartwig, Proceedings of the 2nd Conference on Applied 

Belorossov, S. I. Kryukov, and M. I. Farberov, Nauch. Konf Yaroslav, tekhnol. 

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The reaction of perfluoroalkenes with alkaline hydrogen peroxide is a good general method for the preparation of the corresponding epoxides with the exception of the most reactive of the series, TFEO (eq. 6). 

Weak to moderate chemiluminescence has been reported from a large number of other Hquid-phase oxidation reactions (1,128,136). The Hst includes reactions of carbenes with oxygen (137), phenanthrene quinone with oxygen in alkaline ethanol (138), coumarin derivatives with hydrogen peroxide in acetic acid (139), nitriles with alkaline hydrogen peroxide (140), and reactions that produce electron-accepting radicals such as HO in the presence of carbonate ions (141). In the latter, exemplified by the reaction of h on(II) with H2O2 and KHCO, the carbonate radical anion is probably a key intermediate and may account for many observations of weak chemiluminescence in oxidation reactions. 

Stronger oxidizing agents such as chlorine, bromine, permanganate, chromate, or alkaline hydrogen peroxide oxidize thiosulfate quantitatively to... 

Hair bleaching removes the pigment melanin from the hair shaft by oxidative destmction. Alkaline hydrogen peroxide is the agent of choice. 

The hydroboration step, being very sensitive to steric effects, yields only secondary alkylboranes from trisubstituted double bonds, whereas the less hindered alkylborane is formed predominantly from disubstituted steroidal double bonds. The diborane attack occurs usually towards the a-side and hence results in overall a-hydration of double bonds after alkaline hydrogen peroxide oxidation. ... 

The high degree of stereoselectivity associated with most syntheses and reactions of oxiranes accounts for the enormous utility of these systems in steroid syntheses. Individual selectivity at various positions in the steroid nucleus necessitates the discussion of a collection of uniquely specific reactions used in the synthesis of steroidal epoxides. The most convenient and generally applicable methods involve the peracid, the alkaline hydrogen peroxide and the halohydrin reactions. Several additional but more limited techniques are also available. 

Double bonds in a,/3-unsaturated keto steroids can be selectively oxidized with alkaline hydrogen peroxide to yield epoxy ketones. In contrast to the electrophilic addition mechanism of peracids, the mechanism of alkaline epoxidation involves nucleophilic attack of hydroperoxide ion on the con-... 

Thus, reaction of 3 -acetoxypregna-5,16-dien-20-one (48) with alkaline hydrogen peroxide produces the 16a,17a-epoxide in 95 % yield, and only a 2% yield of the 16, 17 -epoxide. ... 

Nonconjugated double bonds fail to react with alkaline hydrogen peroxide, e.g., see ref. 53, 54 and 56a. The 1,2-double bond of A " -3-ketones e.g., 61, reacts with alkaline peroxide to give the la,2a-epoxide in over 70% yield.""... 

Many functional groups are stable to alkaline hydrogen peroxide. Acetate esters are usually hydrolyzed under the reaction conditions although methods have been developed to prevent hydrolysis.For the preparation of the 4,5-oxiranes of desoxycorticosterone, hydrocortisone, and cortisone, the alkali-sensitive ketol side chains must be protected with a base-resistant group, e.g., the tetrahydropyranyl ether or the ethylene ketal derivative. Sodium carbonate has been used successfully as a base with unprotected ketol side chains, but it should be noted that some ketols are sensitive to sodium carbonate in the absence of hydrogen peroxide. The spiroketal side chain of the sapogenins is stable to the basic reaction conditions. 

Epoxidation of a, -Unsaturated Ketones with Alkaline Hydrogen Peroxide ... 

Acetylenedimagnesium bromide, 66, 84, 137 Acyl-alkyl diradical disproportionations, 299 Acyl-alkyl diradical recombination, 296 Alkaline hydrogen peroxide, 10, 12, 20 Alkylation of formyl ketones, 93 Alkylation via enolate anions, 86 17a-Alkynyl steroids from 17-ketones, 67 2a-Al]yl-17jS-hydroxy-5a-androstan-3 -one, 9 5 Allylic acetoxylation, 242 Allylmagnesium bromide, 64 17 -Aminoandrost-5-en-3 -ol, 145 17 a-Aminomethy 1-5 a-androstane-3, 1718-diol, 387... 

The conversion of 2 -hydroxychalcones to 2-aryl-3-hydroxy-4f/-lbenzopyran-4-ones (flavonols) by alkaline hydrogen peroxide oxidation is known as the Algar-Flynn-Oyamada (AFO) reaction or AFO oxidation. ... 

The Dakin reaction proceeds by a mechanism analogous to that of the Baeyer-Villiger reaction. An aromatic aldehyde or ketone that is activated by a hydroxy group in the ortho or para position, e.g. salicylic aldehyde 12 (2-hydroxybenzaldehyde), reacts with hydroperoxides or alkaline hydrogen peroxide. Upon hydrolysis of the rearrangement product 13 a dihydroxybenzene, e.g. catechol 14, is obtained ... 

An important stage in the synthesis has been reached. The reaction processes described thus far have proceeded uneventfully and have culminated in the synthesis of compound 9. The stage is now set for an evaluation of the first of two hydroboration reactions. Treatment of 9 with diborane in THF, followed by standard alkaline hydrogen peroxide workup, furnishes an 8 1 stereoisomeric mixture of alcohols in favor of 28 (85 % total yield). On the basis of some important precedent,32 it is presumed that compound 9 preferen-... 

Epoxyeyclohexanone has been prepared in 30% yield4 by epoxi-dation of 2-cyclohexen-l-one with alkaline hydrogen peroxide, using a procedure described for isophorone oxide (4,4,6-trimethyl-7-oxabicyclo[4.1.0]heptan-2-one).5 A better yield (66%) was obtained using f r/-butyl hydroperoxide (1,1-dimethylethylhydroperoxide) and Triton B in benzene solution.6 The procedure described here is simple and rapid. 

Alkaline hydrogen peroxide oxidizes polysulfides to sulfate, e.g. ... 

The most widely used reaction of organoboranes is the oxidation to alcohols, and alkaline hydrogen peroxide is the reagent usually employed to effect the oxidation. The mechanism, which is outlined below, involves a series of B to O migrations of the alkyl groups. The R—O—B bonds are hydrolyzed in the alkaline aqueous solution, generating the alcohol. 

The reaction is usually performed at low temperatures, and sometimes water has been used as solvent. For example, cyclooctene is ozonized in the presence of an emulsifier (polyoxyethylated lauryl alcohol) with aqueous alkaline hydrogen peroxide to give a,co-alkanedi-carboxylic acid in one pot (Eq. 3.21).91... 

All gaseous sulfur products obtained as a result of incubation of sulfur-treated fruit were oxidized with alkaline hydrogen peroxide, precipitated as barium sulfate, and counted with a thin window Geiger counter. The peel and peel proteins were oxidized with magnesium nitrate, the sulfur was precipitated as barium sulfate according to standard methods, and counted as in the case of the gaseous products. Counting data, as reported, are fully corrected. 

A calorimetric study of the alkaline hydrogen peroxide conversion of organic nitriles to amides was undertaken. The reaction showed potential for runaway if carelessly scaled up. 

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. 

Finally, the hydrazide 29 98> is strongly fluorescent in neutral solution (e.g. in dioxane), the fluorescence intensity amounting to about 200% of that of 7-dimethylamino-naphthalene-1.2 dicarboxylic hydrazide 30, which is one of the best chemiluminescent hydrazides 97b The 5-isomer, however, is very poor in chemiluminescence in an aqueous system (hemin-catalyzed oxidation with aqueous alkaline hydrogen peroxide), the light yield being only 1 % of that of the 7-isomer in DMSO/t-Bu0K/02 its quantum yield is slightly better but very distinctly below that of 30 98>">. It should be mentioned that in aqueous alkaline solu-... 

The chemiluminescence of luminol in aqueous alkaline hydrogen-peroxide oxidation is catalyzed by many metal ions (see K. Weber and coworkers 184), A. K. Babko and coworkers 185 b p. 159). This catalytic... 

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