Oxidation 4-nitroperbenzoic acid

Thus, Mathis et al. [1, 2] investigated oxidation reactions with 4-nitroperbenzoic acid, sodium hypobromite, osmium tetroxide and ruthenium tetroxide. Hamann et al. [3] employed phosphorus oxychloride in pyridine for dehydration. However, this method is accompanied by the disadvantages that the volume applied is increased because reagent has been added and that water is sometimes produced in the reaction and has to be removed before the chromatographic separation. 

The oxidation of indole magnesium bromide and its 2- and 3-methyl derivatives at room temperature with p-nitroperbenzoic acid, in the absence of light and air, results in the formation of 3-bromoindole (370), 3-bromo-2-methylindole (371), and 2-bromo-3-methylindole (372), respectively. ... 

The 1-hydroxyindoles (78 R = Ph, 2-pyridyl, C02Me) are rapidly oxidized by 4-nitroperbenzoic acid to the corresponding isatogens (79).18,47 The exploitation of this synthesis awaits the development of efficient general syntheses of 78. Recently an electrochemical method has been described.51 52... 

During the course of a kinetic study on the oxidation of tnuu-stilbene with peroxyphosi oric acid (HsPOs), Ogata and coworkers observed the unexpected oxidation of the reaction solvent tetrahydrofuran to y-butyrolactone. However, although n-butyl ether was also oxidized by this reagent, tetrahydropy-ran and dioxane were apparently inert. Ethers undergo oxidation on treatment with 4-nitroperbenzoic acid in chloroform. Moderate yields of esters and lactones are obtained when simple ethers are treated with calcium hypochlorite. 7 At room temperature, reaction times of 4-16 h are necessary. However, primary and secondary alcohols are readily oxidized under these conditions. 

Hydroxylatiott. Tertiary C—H bonds of alicyclic hydrocarbons are oxidized to the corresponding alcohols by p-nitroperbenzoic acid. Unlike the oxidation with trifluoroperacetic acid (7, 281-282), the reaction occurs regioselectively and with practically complete retention of configuration, and thus is comparable to dry ozonation (6,440). 

Peracetic acid was later replaced by m-chloroperbenzoic acid (MCPBA), which is easier to handle and relatively more stable than peracetic acid. Other solid per-acids including chiral peracids have been used in the synthesis of chiral oxaziridines (see Section IIl.l). Recently, MCPBA has been found to be effective in the preparation of oxaziridines with no substituent on the ring nitrogen, a class of oxaziridines that are rather unstable (Ref. 13 and references cited therein). Phase-transfer catalysis has been employed in an improved synthesis of Msulfonyloxa-ziridines. p-Nitroperbenzoic acid was used to oxidize an epoxy imine to an epoxyoxaziridine. ... 

The intermediacy of oxaspiropentanes was first proposed in some reactions i.e. the addition of diazomethane to cyclohexanone the reaction of dimethyloxosulphonium methylide with a-haloketones and the reaction of iV,iV-dimethylaminophenyloxo-sulphonium cyclopropylide with ketones . The parent oxaspiropentane (115) has been obtained from the p-nitroperbenzoic acid oxidation of a methylene chloride solution of methylenecyclopropane (69) at - 10°C (equation 82). ... 

Xylitol has been derived from the product of photo-oxidation of cyclopentadiene [204], (Z)-(4RS)-4,5-epoxypent-2-enal (Scheme 13.105). Chemoselective reduction of the formyl group gives cis-hydroxyepoxypentene 448, which is directly acetylated into 449. Treatment of 449 with tetrabutylammonium acetate in AC2O opens the epoxide with formation of 450. De-O-acetylation gives 451, the epoxidation of which with p-nitroperbenzoic acid generates a 3 7 mixture of epoxides 452 and 453, isolated as peracetates. The major epoxide 453 is hydrolyzed into xylitol via the orthoester 454. 

With p-nitroperbenzoic acid (112) led to (113), reduced with lithium aluminium hydride to (114). Oxidation of (114) afforded the lactone (115), so demonstrating the la-lOa stereochemistry of the oxiran ring of (113). 

Of all the rearrangement reactions of vincadifformine, the one that has been the subject of the most intensive investigations is the rearrangement to vincamine. The earliest studies were summarized in Volume 17 (1). These include the oxidation of vincadifformine (76) by means of p-nitroperbenzoic acid, followed by treatment of the intermediate 16-hydroxyindoIenine Aft-oxide (284) so formed with triphenylphosphine and acetic acid. The N-oxide function in 284 was thereby reduced, and the resulting hydroxyindo-lenine 285 rearranged to a mixture of vincamine (286) and 16-epivincamine... 

Oxidative rearrangement of 28 with m-chloroperbenzoic acid followed by hydrogenation gave vincamine (277) and epivincamine (299) in the ratio 1 6.5. Reversal of the reaction sequence and the use of p-nitroperbenzoic acid gave 277 and 299 in the ratio 4 1 (303). 

Different HALS stabilizers were added to coatings and cured on quartz plates or disks described above. Nitroxide concentration was quantified as a function of exposure time via the primary standard, I. The total amount of parent HALS and HALS-based inhibition cycle products was determined by oxidizing CH2CI2 extracts with p-nitroperbenzoic acid. " ... 

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