With 3-Chloroperoxybenzoic Acid

Phenyl alkyl telluriums and phenyl eycloalkyl tellurium eompounds were oxidized in tetrahydrofliran or in methanoP with 3-chloroperoxybenzoic acid to the corresponding 

Irgolic Organo Tellurium Compounds with 2 Te —C Bonds or 1 Te = C Bond 

---

Thermolysis (115°C) or irradiation of the epoxide 3, generated from bicyclo[2.2.0]hexa-2,5-diene ( Dewar benzene") with 3-chloroperoxybenzoic acid, gives a mixture of the valence tautomers oxcpin and benzene oxide together with traces of phenol.111112... 

In contrast to the attempts with 3-benzothiepins, furo[3,4-r/]thiepin is readily oxidized with 3-chloroperoxybenzoic acid to the corresponding S-oxide and S, 5-dioxide, which have been characterized by H NMR and UV spectra.71... 

Treatment of ethyl 2,7-di-/ert-butylthiepin-4-carboxylate (24) with 3-chloroperoxybenzoic acid at — 78 °C results in the benzene derivative 25 only, and no sulfur-oxidized products 80 however, the stable 2,7-di-ter/-butylthiepin (26) can be oxidized with 0-benzyl 00-hydrogen monoper-oxycarbonate at — 78 °C to give the corresponding S-oxide 27, which was monitored by HNMR spectroscopy at — 40°C. At —15 C, sulfoxide 27 was converted, via extrusion of sulfur monoxide, with a half-life of 5.5 hours to the benzene derivative 28.87 The oxidation reaction of 26 with excess of the monoperoxycarbonate did not proceed to the S,S-dioxide, even though the parent thiepin 1,1-dioxide is known to be stable at room temperature.15... 

Dialkyl-5//-dibenz[/>,/]azepines 6 on oxidation with 3-chloroperoxybenzoic acid undergo ring contraction to 9,10-dihydroacridinc-9-carbaldehydes 7.223 In contrast, 5,10,11-trialkyl derivatives 8 yield mixtures of the acridinyl ketones 9 and 10,11-epoxides 10. 

Reduction of the 1//-1,2-benzodiazepines 6 with lithium aluminum hydride results in the dihydro compounds 8, which are dehydrogenated to the 3H-1,2-benzodiazepines 9 by 4-phenyl-4//-l,2,4-triazole-3,5-dione.123 The products readily revert to the 1//-tautomers in the presence of sodium methoxide. 3//-1,2-Benzodiazepines react with 3-chloroperoxybenzoic acid to give mixtures of 1- and 2-oxides, 10 and 11, in which the latter predominate. Treatment of the 2-oxides 11 with nucleophiles provides 3-substituted H- 1.2-benzodiazepines 12. Selected examples are given.124... 

Oxidation of benzodiazepinone 1 with 3-chloroperoxybenzoic acid gives a mixture of the oxaziridine 2 (10%) and the benzodiazepinone 4-oxidc 3 (40%).165... 

Diazaquinones 68, 83a, and 90 have been shown to provide adducts with various isoprenoids, as exemplified by the /3-myrcene adduct 140 (87H193). The side-chain double bonds of these adducts can be functionalized by epoxidation with 3-chloroperoxybenzoic acid or via bromination with IV-bromosuccinimide to provide the corresponding derivatives 141 and 142, respectively (Scheme 34). 

Ring-opened products were obtained from pyrido[l,2-6]cinnolin-6-ium hydroxide inner salt (17, R = H) by oxidation with 3-chloroperoxybenzoic acid, or by reduction with Zn in acetic acid, and from the 5-methyl derivative 43 by reduction with Zn in acetic acid (74JHC125). 

Formation of CK-configurated cyclobutanones has also been observed with 2-methylcyclopen-tanone and 2-methylcyclohexanone/8 However, stereoreversed eyclobutanone formation can be achieved by opening the intermediate oxaspiropentane with sodium phenyl selenide, oxidation of the resulting / -hydroxy selenide with 3-chloroperoxybenzoic acid and subsequent rearrangement in the presence of pyridine/18 Thus, from one oxaspiropentane 8, either stereoisomeric eyclobutanone cis- or lrans-9 was produced. The stereoreversed eyclobutanone formation proceeds from a stereohomogenous / -hydroxy selenoxide and is thought to be conformationally controlled. 

A more rapid reaction is observed when an alkoxy group is situated on the a-carbon and for such compounds 3-chloroperoxybenzoic acid is preferred. For example, (n + 9)-oxatricy-clo[5.n + 2.0.015]alkan-2-ones 4 reacted with 3-chloroperoxybenzoic acid to give 2,(n -I- 10)-dioxatricyclo[6.n + 2.0.01,6]alkan-3-ones 5 which were hydrolyzed to the cyclobutanones.26... 

Reactions on similar compounds have been reported and in these cases only the cyclobutanones were isolated after in situ hydrolysis.26,30 For example, ll-oxatricyclo[6.3.0.01,6]undecan-2-one (6), 10-oxatricyclo[5.3.1.01,6]undecan-2-one (7) and (n + 10)-oxatricyclo[6.(n + 2).0.01,6]alkane-2,(n + 9)-dione (8) all gave good to excellent yields of the cyclobutanones after reaction with 3-chloroperoxybenzoic acid followed by hydrolysis. 

A limitation of the ring expansion reaction is seen when a cyclobutanecarbonyl chloride is reacted. While treatment of D-nor-5a-androstane-16a-carbonyl chloride with 3-chloroperoxybenzoic acid gave the normal product D-nor-5a-androstan-16a-ol (9) via the acyl aroyl peroxide, the only isolated product from the epimer D-nor-5a-androstane-16/ -carbonyl chlo-... 

Nearly all examples of epoxidation of alkylidenecyclobutanes involve 3-chloroperoxybenzoic acid.15 58-70 This is because the conditions are mild, the workup is easy and few byproducts are formed. Generally, dichloromethane or chloroform is used as solvent. Solid sodium hydrogen carbonate is occasionally added to avoid acid-catalyzed rearrangement of the spiro compound. For example, 6-isopropylidene-l,4,4-trimethylbicyclo[3.2.0]heptan-3-one reacted with 3-chloroperoxybenzoic acid and sodium hydrogen carbonate to give 2,2,3, 3, 6-pentamethyl-spiro[3-oxabicyclo[4.2.0]octane-8,2 -oxirane]-4-one (4) in quantitative yield. However, without the use of sodium hydrogen carbonate, substantial amounts of 2,2,6,9,9-pentamethyl-3-oxa-bicyclo[4.3.0]nonane-4,8-dione (5) and 2,2,6,8,8-pentamethyl-3-oxabicyclo[4.3.0]nonane-4,9-dione (6) were also formed.15-64... 

More recently, various reports on the use of /cr/-butyl hydroperoxide and hexacarbonylmolyb-denum70 or acetylacetonatovanadium71 have appeared. For example, treatment of 3-oxatricy-clo[6.4.0.02,7]dodec-6-en-l-ol with 3-chloroperoxybenzoic acid gave 3,7-dioxatetracy-clo[7.4.0.02,4.02,8]tridecan-9-oI (7) in 85% yield, while with /crt-butyl hydroperoxide in the presence of hexacarbonylmolybdcnum gave 7 in 66% yield.70... 

Oxidation of 6-oxopyrido[2,l-h][l,3]thiazine-4,9-dicarboxylates (85 n = 0, R = H, phthalamido) with 1 mol eq of 3-chloroperoxybenzoic acid yielded sulfoxides (85 n = 1, R = H, phthalamido) [83JCS(CC)199 92JCS(P1)621]. Oxidation of 2,3,4,6,7,llh-hexahydro[l,3]thiazino[2,3-a]-isoquinolin-4-ones with 3-chloroperoxybenzoic acid in dichloromethane gave sulfones (69FRP1552211). The appropriate sulfone was also prepared from perhydropyrido[2,l-h][l,3]thiazine (59AP165) and 3,4,7,8, 9,10-hexahydro-2//,6//-[ 1,3]thiazino[3,2-h] isoquinolin-6-one [79JAP(K)79/ 92996 81USP4284778]. 

The method of Kim et al.[89-93] starts from the synthesis of the three-carbon phosphonium salt according to the modified method of Corey et alJ94,95] The Wittig reaction of the phosphonium salt with a Z-protected a-amino aldehyde using potassium hexamethyldisilazanide provides the ds-alkene without racemization. Efficient hydrolysis of the orthoester without double bond migration is achieved by acidolytic hydrolysis with aqueous hydrochloric acid in tert-butyl alcohol under reflux conditions. Then, an a-amino acid methyl ester is coupled. The desired epoxide product is obtained by treatment with 3-chloroperoxybenzoic acid. The epoxidation reaction is stereoselective and predominantly provides one isomer (R,S S,R = 4-10 1). The trans-epoxide can also be prepared using a trans-alkene-containing peptide. A representative synthetic procedure to obtain the ds-epoxide isostere is detailed below. 

Treatment of sec-alkyl phenyl telluriums with 3-chloroperoxybenzoic acid in diethyl ether gave olefins in good yields. The reactions, which are postulated to proceed via a telluroxide intermediate, convert the alkyl halides used in the preparation of the alkyl phenyl telluriums to olefins1. 

Cyclohexyl phenyl tellurium reacted with 3-chloroperoxybenzoic acid to form cyclohexyl phenyl tellurium hydroxide benzoate that decomposed at 250° to give cyclohexene (19% yield)1. A similar sequence of reactions starting with phenyl 1-tetradecyl tellurium produced 1-tetradeccne (42%), 1-tetradecanol (7%), and 1-tetradecanal (2%). ... 

When 2-methoxycycloalkyl phenyl telluriums, prepared from cycloalkenes and phenyl tellurium trichloride in methanol, are treated with 3-chloroperoxybenzoic acid, the elimination of the phenyltelluro group is accompanied by ring-contraction and formation of the dimethyl acetals of formylcycloalkanes2 3. 

Oxidation of the ethylene acetals of 3-aryl-3-oxo-2-propyl phenyl telluriums, which were prepared from the acetals of 3-aryl-3-oxo-2-bromopropane and arenetellurolates, with 3-chloroperoxybenzoic acid in methanol at 20° produced hydroxyethyl 2-arylpropanoates2. Tellurones were postulated as intermediates that experienced a 1,2-aryl shift and the elimination of an aryltelluro moiety. 

Reacting alkyl phenyl tellurium oxides with 3-chloroperoxybenzoic acid in methanol or ethanol at 20° produced alkyl methyl (ethyl) ethers3,4. 

Decene and phenyl tellurium tribromide reacted in methanol to produce 2-methoxydecyl phenyl tellurium dibromide, which was hydrolyzed to the tellurium oxide. Treatment of the tellurium oxide with 3-chloroperoxybenzoic acid in methanol give 1,2-dimethoxydecane in 84% yield5,6. 

When 2-phenyl-2-methoxy-2-R-ethyl or -propyl phenyl telluroxides (obtained from phenylethylenes and phenyl tellurium tribromide in methanol followed by hydrolysis of the tellurium dibromide) were treated with 3-chloroperoxybenzoic acid in methanol at 20°, the phenyl group migrated to the methylene group from which the tellurium moiety had been... 

Reaction of [NEt4]2[MoS4] with tetraethylthiuramdisulfide afforded the paramagnetic molybdenum(V) complex [Mo(S2)(S2CNEt2)3] (S = 1/2). This reacted with 3-chloroperoxybenzoic acid to give [Mo(S20-5, 5 )(S2CNEt2)3]... 

The general trend discussed above is also manifest in the epoxidation of 3-ethylcyclohexene. Whereas epoxidation with 3-chloroperoxybenzoic acid yields both diastereomers in almost equal proportions, the molybdenum-catalyzed reaction affords the epoxides from tram attack with more than 80 20 selectivity103 (for a general discussion of diastereoselectivity of peracid epoxidation of 3-methylcycloalkenes, see Section 4.5.1.1.4.3.). 

Epoxidation of 3-Arylideneflavanones (E)- a with 3-Chloroperoxybenzoic Acid Typical Procedure20 ... 

In a triphasic system, poly-(S)-alanine IV-butylamide (4) with 3-chloroperoxybenzoic acid was shown to be a surprisingly good combination for chiral epoxidation of chalcone (5)12-13. The enantiomeric excess of the products increased dramatically with molecular weight (e.g., n = 5, ee = 11 % n = 30, ee = 96 %). 

Oxidation of -substituted allylic sulfides with 3-chloroperoxybenzoic acid or periodate usually yields S-epimeric sulfoxides, which can be directly subjected to the rearrangement to give optically active allyl alcohols. The enantiomeric excess is determined by the preference of the transoid transition state over the cisoid transition state. 

Benzofuroxan (benzofurazan 1-oxide, 1) reacts with readily enolizable cyclohexane-1,2-dione in the presence of a secondary or tertiary amine to give a mixture of phenazine-l-ol mono- and di-jV-oxides. In order to improve the yield of the dioxides, the mixture obtained can be treated without further separation with 3-chloroperoxybenzoic acid in benzene. ... 

Phenazine-1.6-diol 5,10-dioxide (iodininc) can be easily prepared from phenazine-l,6-diol by peroxyacid oxidation. Oxidation of 1,6-dimethoxyphenazinc (3) with 3-chloroperoxybenzoic acid affords 1,6-dimethoxyphenazine 5-oxide (4) and 1. b-dimethoxyphenazine 5,10-dioxide... 

---