Peroxybenzoic acid oxidant

Baeyer-Villiger oxidation is a ketone oxidation, and it requires the extremely strong oxidizing agent peroxybenzoic acid. For example, peroxybenzoic acid oxidizes phenyl methyl ketone to phenyl acetate (an ester). 

The configuration of the products obtained by the anodic method 0/a = 13.9) shows a remarkable similarity with the microsomal oxidation products (P/a = 14.1), whereas peroxybenzoic acid oxidation exhibits poor stereospecificity (P/a = 3). ... 

Wood and Fletcher have reinvestigated the peroxybenzoic acid oxidation of D-galactal, and have isolated a crystalline n-talose monobenzoate which they have shown to be a-D-talopyranosyl benzoate (38), the product to be expected, from the above considerations. Twenty years earlier, Pigman and Isbell had described the isolation, from this reaction, of a different monobenzoate which they believed to be a 1,2-orthoester but later, in view of its carbonyl absorptions in the infrared region, Isbell and coworkers amended the assignment to that of a 1-benzoate. This compound is, therefore, considered to be /S-n-talopyranosyl benzoate it may have arisen by anomerization of the a-n anomer (38). 

Using Figure 17 15 as a guide write a mechanism for the ] Baeyer-Villiger oxidation of cyclohexyl methyl ketone by peroxybenzoic acid J... 

It is possible to introduce this group selectively onto a primary alcohol in the presence of a secondary alcohol. The derivative is stable to KMn04, w-chloro-peroxybenzoic acid, LiAlH4, and Cr03 Pyr. Since this derivative is similar to the p-methoxyphenyl ether it should also be possible to remove it oxidatively. The GUM ethers are less stable than the MEM ethers in acid but have stability comparable to that of tlie SEM ethers. It is possible to remove the GUM ether in the presence of a MEM ether. 

The reactions of arenediazonium ions with 7V-alkyl- or 7V-arylhydroxylamines were investigated by Bamberger (1920b, and earlier papers). Mitsuhashi et al. (1965) showed that the l,3-diaryl-3-hydroxytriazenes are tautomeric with 1,3-diaryltriazene-3-oxides (Scheme 6-16). Oxidation of 1,3-diaryltriazenes with peroxybenzoic acid in ether yields the same product as that from diazonium salts and TV-arylhydroxyl-amine. The infrared spectrum of the product obtained by coupling diazotized relabeled aniline with A/-phenylhydroxylamine indicates that the diaryltriazene-oxide is the preponderant tautomer. 

The analytical method described is also used in following the consumption of peroxybenzoic acid or other peroxy acids during an oxidation reaction it has also been used in determining the conversion of other carboxylic acids to peroxy acids when solvent extraction has been used in the isolation. 

Malonic acid, amino-, diethyl ester, HYDROCHLORIDE, 40, 24 Malonic acid, bts(hydroxymethyl)-, DIETHYL ETHER, 40, 27 Malonitrile, condensation with tetra-cyanoethylene, 41, 99 2-Mercaptopyrimidine, 43, 6S hydrochloride of, 43, 68 Mercuric oxide in preparation of bromo-cyclopropane, 43, 9 Mesityl isocyanide, 41,103 5-Methallyl-l,2,3,4,5-pentachlorocyclo-pentadiene, 43, 92 Methane, dimesityl-, 43, 57 Methanesiileinyl chloride, 40, 62 Methanesulfonic acid, solvent for making peroxybenzoic acid from benzoic acid, 43, 93... 

Peroxybenzoic acid readily oxidizes aryl and alkyl sulphoxides in acetone, methylene chloride or chloroform solutions, to the sulphone in high yield . The reaction is second order and acid catalysed as is the reaction with peracetic acid . The rate of oxidation is about five times faster than when peracetic acid is used. Other work considering the oxidation of sulphoxides with peracids gathered kinetic evidence and showed that the reaction was indeed second order and that the reaction involved nucleophilic attack by the sulphoxide sulphur atom on the peracid moiety. A further study by the same authors showed that with benzyl and phenyl alkyl sulphoxides the rate of reaction was very sensitive to the inductive effect of the alkyl group. Support for the nucleophilic attack by the sulphur atom on the peracid in acidic solution was forthcoming from other sources . ... 

Irradiation of toluene in the presence of chlorine yielded benzyl hydroperoxide, benzaldehyde, peroxybenzoic acid, carbon monoxide, carbon dioxide, and other unidentified products (Hanst and Gay, 1983). The photooxidation of toluene in the presence of nitrogen oxides (NO and NO2) yielded small amounts of formaldehyde and traces of acetaldehyde or other low molecular weight carbonyls (Altshuller et al, 1970). Other photooxidation products not previously mentioned include phenol, phthalaldehydes, and benzoyl alcohol (Altshuller, 1983). A carbon dioxide yield of 8.4% was achieved when toluene adsorbed on silica gel was irradiated with light X >290 nm) for 17 h (Freitag et ah, 1985). 

Oxepane (1), as a typical ether, is susceptible to oxidation and yields oxepan-2-one (78) as the initial product. Adipic acid was the product finally isolated after oxidation with Ru04 and NaI04 in a two-phase system (80SC205) or oxygen in the presence of a Pt catalyst (76CB3707) (Scheme 9). Oxidation of 2,3,6,7-tetrahydrooxepin (79) has been reported with peroxybenzoic acid or osmium tetroxide to yield the epoxide (80) or the cis diol (81) respectively (Scheme 10) (58JA3132). 

The Baeyer-Villiger oxidation of cyclohexanone to form e-caprolactone (78) using peroxybenzoic acid, as indicated in equation (40), may be considered as a further type of intramolecular displacement reaction of value in seven-membered ring synthesis (49JA2571). 

Inclusion of electron-deficient subrings is accomplished by reaction of dione (61) with hydrazine, followed by dehydrogenation (74JA5287). Oxidation of (73) with peroxybenzoic acid affords the mono-AC-oxide (74), a chiral ansa compound. 

Baeyer-Villiger oxidation of cyclohexyl methyl ketone by peroxybenzoic acid. 

Trifluoroacrylonitrile can be epoxidized by oxygen with 1,1,2-trichlorotrifluoroethane (CFC-113) as a solvent under pressure at elevated temperatures in moderate yield (Table 2).77 Substituted peroxybenzoic acids are used for the epoxidation of trifluorovinyl alkenes with attached functionalities such as ester, amide or dimethoxyphosphoryl groups (Table 2).7S Functional derivatives of perfluoro-2-methylprop-2-enoic acid are oxidized to the corresponding epoxy compounds in this reaction.78 In the case of ethyl ester 40, the epoxide 41 is contaminated with the adduct of 3-chloroperoxybenzoic acid to the C = C bond, compound 42, that is formed even at low temperatures.78... 

A similar reaction is observed for cyclic sulfilimines. For example, octafluorotetrahydro-1//-l/l4-thiophene-1-imine is easily oxidized to the 1-iminc 1-oxide (sulfoximine) by 3-chloro-peroxybenzoic acid (Table 19).307... 

Benzoylhydroperoxide or Benzoyl hydrogen Pei oxides See Perbenzoic(Peroxybenzoic) Acid... 

Computational studies showed that the nature of the reactive species in the oxidation of trimethylamine, iodide ion, and dimethyl sulfide with lumiflavin is a C4 a-hydroperoxide complexed with water. The other two species, C4 a-hydroperoxide and C4 a-peroxide, yielded higher activation energies.237 Kinetic and spectroscopic studies on the effect of basic solvents, ethers, esters, and amides, on the oxidation of thianthrene-5-oxide with substituted peroxybenzoic acids indicated the involvement of the basic solvent in the transition state of the reactions. A solvent parameter, Xtc, based on the ratio of the trans to the cis form of thianthrene-5,10-dioxide, has been introduced.238... 

With peroxybenzoic acid or bis(trimethylsilyl)peroxide, II can be oxidized to cis-l,6-dimethyl-II-oxa-l,6-disila-[4,4,l]-undecane (III). This compound can be obtained only in the cis form since in the trans form the ring straining is too great... 

The same products are also obtained by oxidation of the dienol acetates with peroxybenzoic acid or by oxidation of the corresponding enones with the liver microsomal oxidation systems. 

Epoxidations and Baeyet Villiger oxidations. This peroxy acid resembles peroxytrifluoroacetic acid in activity, but buffers are not necessary. The report includes two successful epoxidations with the new peroxy acid (and also p-nitro-peroxybenzoic acid) for which peroxytrifluoroacetic acid was of no value. 

Instead of acetates also free aldehydes may be oxidized The oxidation of acrolein is carried out at 313 K in benzene For polyCu- and polyFePc, pyridine is needed to activate the oxidation. From benzaldehyde and others a mixture of benzoic acid and peroxybenzoic acid is produced with Cu- and FePc derivatives (95) (prepared from TCB and metal dilorides in ethylene glycol) (Eq.45) The reactions were carried out in various solvents at %3 K. 

Oxidations with peroxybenzoic acid are carried out in solutions in dichloromethane, chloroform, benzene, ether, or ethyl acetate at or below room temperature and include epoxidation of double bonds [295, 296, 297, 298, 299, 300, 301], oxidation of benzaldehydes to carboxylic acids or phenols [302], the Baeyer-Villiger reaction of ketones [303, 304, 305, 306, 307], and oxidation of sulfides to sulfoxides [308, 309]. Peroxybenzoic acid is also used for the anti hydroxylation of double bonds [310], the oxidation of pyrrolidines to pyrrolidones [377] and of pyrroles to succinimides [377], and the preparation of azoxy compounds from azo compounds [372]. 

Epoxidation takes place preferentially or more rapidly at electron-rich (i.e., tetraalkylated) double bonds [217]. The reaction is stereospeciflc cis alkenes give cis epoxides, and trans alkenes give trans oxides [211. 1,2-Dimethylcyclopentene is oxidized with peroxybenzoic acid to 1,2-di-inethylcyclopentene oxide in 85% yield [296], and dj-cyclooctene is transformed by hydrogen peroxide into c -cyclooctene oxide in 60-61% yield [1099]. 

Oxidations of aromatic aldehydes to formyl esters of phenols and to phenols are accomplished by hydrogen peroxide [171, 172, 173] or by organic peroxy adds such as peroxyacetic acid [259], peroxybenzoic acid [302], and m-chloroperoxybenzoic acid [5/5, 318] (equations 360-363). 

Peroxybenzoic acid is used to oxidize cycianones [iOi], as well as alkyl and phenyl cycloalkyl ketones [304, i05]. Yields of cycloalkyl acetates obtained on treatment of cycloalkyl methyl ketones with a 10-15% stoichiometric excess of peroxybenzoic acid in chloroform at room temperature range from 58 to 72% (equation 385) [305]. 

Cyclohexyl phenyl ketone oxidized by peroxybenzoic acid in chloroform at 24-26 °C for 239 h furnishes an 85% yield of esters, of which 71% is cyclohexyl benzoate and 14% is phenyl cyclohexanecarboxylate. This result shows that the migratory aptitude of the cyclohexyl group is 5 times greater than that of the phenyl group [304]. 

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