Peracetic acid, oxidation with

Peracetic acid oxidation of 2,5-diphenyl-l,4-dithiadiene-l-oxide produces 2,5-diphenyl-l,4-dithiadiene-l, 1-dioxide in 72% yield without reaction with the sulphide sulphur atom40 (equation 13). This is rather surprising given the earlier evidence concerning relative rates37. 

Ether solvents, such as THF, diethyl ether etc. are unsuitable solvents for peracetic acid oxidations, as interaction of the acid with the peroxidisable solvent is violent. 

Cyclodehydration of 2-phenylthiocyclohexanone with a variety of reagents yielding 1,2,3,4-tetrahydrodibenzothiophene (64) as an oil has been reported,and represents the simplest way of obtaining this material (88%). Alternatively, reduction of 4-keto-1,2,3,4-tetrahydrodibenzothiophene under Huang-Minlon conditions affords 64 in high yield.Trace amounts of 64 were detected in the reduction of dibenzothiophene with calcium hexamine and during electrolysis in ethylenediamine-lithium chloride solution (Section III, C,4). Peracetic acid oxidizes 64 to its sulfone (65%), which... 

In the presence of acids, linalool isomerizes readily to geraniol, nerol, and a-terpineol. It is oxidized to citral by chromic acid. Oxidation with peracetic acid yields linalool oxides, which occur in small amounts in essential oils and are also used in perfumery. Hydrogenation of linalool gives tetrahydrolinalool, a stable fragrance material. Its odor is not as strong as, but fresher than, that of linalool. Linalool can be converted into linalyl acetate by reaction with ketene or an excess of boiling acetic anhydride [34]. 

In a study of the chemistry of oxaziranes [75], it was discovered that this class of novel heterocyclic compounds is readily oxidized with peracetic acid to give dimeric nitroso compounds. Since the oxaziranes are, in turn, prepared by a peracetic acid oxidation of imines, the crude imines can, by proper adjust-... 

Instead of the peracetic acid oxidation just described, performic acid (prepared from 98 % formic acid and 90% hydrogen peroxide) may also be used as an oxidizing agent for the preparation of nitroso compounds. With this reagent, pentafluoronitrosobenzene and 4-nitrosotetrafluorobromobenzene have been prepared from the respective amines [85]. 

Peracetic acid oxidation of 2-carbamoylquinoxaline (94) at 20°-25° gives the monoxides 95 and 96, and at higher temperatures the 1,4-dioxide (97) is isolated in 50% yield, together with a small amount of the 1,4-dioxide of 2-amino-3-quinoxalinone.m However, Hayashi and co-workers report the isolation of only 96 from 94 using monoperphthalic acid in ether <10°.109 In their attempt to correlate the nature of 2-substitution with the formation of 1- versus 4-oxides, they examined the behavior of some 2-alkyl substituted quinoxalines 113,114 2-ethylquin-oxaline gives the 1- and 4-oxides and the 1,4-dioxide, 2-isopropylquin-oxaline yields the 4-oxide and the 1,4-dioxide however, 2-f-butylquin-oxaline only furnishes the 4-oxide because of steric hindrance.114 The N-oxidation of 2-phenyl- and 2-alkyl-3-phenyl-quinoxalines with monoperphthalic acid furnishes the products shown in Table 1.114... 

Peracetic Acid Decomposition. Although, by comparing the rate of peracetic acid decomposition with the rate of its reaction with acetaldehyde, we can rule out the decomposition as a major path in acetaldehyde oxidation (see below), we will discuss the possible mechanisms for the catalytic decomposition of peracetic acid. 

An alternate mechanism for the cobalt (III)-catalyzed peracetic acid decomposition with a sequence of oxidation-reduction reactions, could be as follows ... 

Suitable control experiments had been carried out to establish that dibutyltin dichloride is not lost from the residue at 50 °C. and 12 mm. and to establish that the procedure for mercaptide removal (peracetic acid oxidation) did not interfere with the accuracy of the chloride analysis. 

Peracetic acid oxidizes l,6,6aA4-trithiapentalenes to l-oxa-6,6aA4-dithiapentalenes, most probably with intermediate formation of 5-oxides (71AHC(i3)16i,p. 180). 

When the 6-position is unsubstituted, oxidative degradation is most common, and peracetic acid treatment leads to ring contraction to form 2,4-disubstituted imidazoles and their N-oxides (81H573). For example, 2-methyl-4-phenylpyrimidine (28) reacts in this way with peracetic acid, but with m-chloroperbenzoic acid in chloroform, pyrimidine N-oxides were formed as well (Scheme 12). Even pyrimidine itself gave the oxide in 48% yield under these latter conditions 2-methylpyrimidine gave 55% of the N-oxide (81H573). 

Oxidation of ketones with non-peracetic acid oxidants. 

Parent and cross diperoxides are produced when tetra-sub-stituted olefins containing suitable substituents are ozonized. Cross diperoxides are also produced when pairs of tetra-substituted olefins are ozonized together. Comparison samples of diperoxides are conveniently synthesized by treating the appropriate ketone with peracetic acid at low temperature. Peracetic acid oxidation of ketone pairs can also be used to prepare cross diperoxides. Low temperature NMR is used to study diperoxide stereochemistry as well as barriers to conformational isomerization. 

Chlorination of tertiary carbon atoms (8, 161). Radical chlorination of the trifluoroacetate 1 with N,N-dichlorourethane gives as one product the 25-chloro derivative 2, which can be converted into the 25-hydroxy derivative 3 by refluxing aqueous ethanol. The corresponding 25-hydroxy-8-ketone has been converted into 25-hydroxyvitamin This method for hydroxylation of C25 is somewhat more selective than dry ozonation or peracetic acid oxidation, both of which hydroxylate all four tertiary carbons, but the yield of 3 is about the same as that obtained directly by dry ozonation. 

Iona group -with jSJaotoma, 826 Carboxylic acida. reaction with axirMUnea, 653 epoxides, 366-82 etliylene auliidea. 612 o,CarboxyiitilbBne, perbenxoic acid Oxi-datlOD, 63, 373 Car-3 ene, epoxidation, 43 AB-Carene, peracetic acid oxidation, 381... 

Dimerization of sulfene yields disulfone 546, whose protons are readily replaced by deuterium, bromine, or trimethylsilyl groups. Sulfone 546 reacts with 2,6-dimethyl-4-pyrone to give an exo-methylene derivative and it may be tetra-methylated. Other disulfones are obtained by oxidation of 1,3-dithietanes with potassium permanganate or chromium trioxide-fuming nitric acid for resistant dithietanes. As mentioned above, peracetic acid oxidizes a disulfoxide, mono-sulfone, or a monosulfone-monosulfoxide to the disulfone 546. 57b,iii3a 2,2,4,4-Tetra(trifluoromethyl)-l,3-dithietane 537 is oxidized only to the monosulfone 547, even with chromium trioxide-hot, fuming nitric acid the disulfone is only... 

The synthesis of tazobactam from 6-APA (Scheme 6.15) proceeded via the 2- -(chloromethyl)penam ester (81 a), which was first prepared by Gottstein and co-workers [47] during the synthesis of 2-/S-(chloromethyl)-2-a-methylpenam-3a-carboxylic acid 1,1-dioxide (29). 6-APA (8) was converted to 6a-bromopenicillanic acid (77) by treatment with sodium nitrite and hydrobromic acid. Oxidation with peracetic acid in the presence of benzophenone hydrazone gave benzhydryl 6a-bromopenicillanate-l-oxide (78) and reduction with zinc and acetic acid gave benzhydryl penicillanate-1-oxide (79). The unsymmetrical azetidinone disulphide (80) was obtained by heating with 2-mercaptobenzothiazole reaction with copper (II) chloride... 

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