M-Chloroperoxybenzoic acid MCPBA

Synthesis of Allylic Alcohol Xa. A 3.84 g sample of olefin VII was treated with m-chloroperoxybenzoic acid (MCPBA) in dichloromethane for 1.5 hours at 0°C and 2.5 hours at 20°C. The NMR spectrum of the crude product indicated a mixture of approximately 75% epoxide VIII and 25% IX (structural assignments based upon assumed epoxidation preferentially from the less hindered side). Purification by column chromatography furnished 0.61 g of IX and 2.58 g of VIII. The separation was performed for characterization purposes the crude epoxidation mixture was suitable for subsequent transformations. 

Synthesis. Oxidation of -alkyl or -benzyl IJ,IJ-dialkylthio-carbamates with one equivalent of m-chloroperoxybenzoic acid (MCPBA) in chloroform or methylene chloride at -25° to 25°C yields the corresponding carbamoyl sulfoxide (3) in essentially quantitative yield (3-5). The -chloroallyl thiocarbamate sulfoxides (e.g., 4-7) are obtained in the same manner except that the temperature is maintained between -20°C and 0°C for the oxidation and extraction of the reaction mixture with 5% sodium carbonate aqueous solution (7, 8). 

Better yields of the mono-oxygenated product and the concurrent generation of higher oxides can be achieved by oxidahon with m-chloroperoxybenzoic acid (MCPBA) (Scheme 8.2) [20-24] Cjq and usually about 10 to 30 equiv. of the peroxy acid are stirred in toluene at 80 °C [21]. The product distribuhon can be influenced by reaction hme and the amoimt of acid. The existence of the C gO-isomer 1 -accessible in 30% yield - and the ds-l-CgQ02-isomer 2 - accessible in 8% yield -could be proven (Scheme 8.2) [21], but higher oxides CggO up to n = 12 can also be formed [24]. The main products are oxides with n = 1-3. 

In 1957, Henbest and Wilson reported hydroxyl-directed epoxidation using m-chloroperoxybenzoic acid (mCPBA) [3]. In the synthetic studies of juvenile... 

B. (+)-trans- -( Pketiyleulfnnyl) -3-phenylexaairidine. A 5-L, three-necked flask is equipped with a mechanical stirrer and a 500-mL pressure-equalizing addition funnel. Into the flask are placed 500 mL of saturated aqueous sodium bicarbonate solution, 12.5 g (0.055 mol) of benzyltriethyl -ammonium chloride (BTEAC) and 122.5 g (0.50 mol) of N-benzylidenebenzene-sulfonamide dissolved in 380 mL of chloroform (Note 7). The reaction mixture is stirred vigorously at 0-5°C in an ice bath while a solution of 111.6 g (0.55 mol) of 85% m-chloroperoxybenzoic acid (MCPBA) dissolved in 1000 mL of chloroform is added dropwise. After the addition of the peracid, which takes about 1 hr, the reaction mixture is stirred for an additional hour at this temperature. A 3-L separatory funnel is used to separate the chloroform... 

The reaction had its origins with the use of peioxyorganic acids. The simplest, formic, peracetic, and perbenzoic acid, are not so much in contemporary use. The workhorse of peroxy acids is m-chloroperoxybenzoic acid (mCPBA). 

The submitters provided the following alternative procedure for conducting the oxidation with m-chloroperoxybenzoic acid (MCPBA) in place of Oxone Into a 1 -... 

Dioxygen oxidation of tetrasila-1,3-butadiene 64 provides unusual oxidation product 151, in which even the sterically well-protected central Si-Si single bond is oxidized together with the two Si = Si double bonds [Eq. (65)].106 In contrast, when m-chloroperoxybenzoic acid (mCPBA) is used as a milder oxidant for the reaction, a mixture of 152 and 153, whose central Si-Si bonds remain intact, is obtained. 

Biooxidation is an essential activation process for some organothiophosphorus neurotoxicants (1). m-Chloroperoxybenzoic acid (MCPBA) has been used to mimic some of these reactions but without identifying the products derived from phosphorothiolates (.2,3). We observed that S-alkyl phosphorothiolates react with MCPBA to form a new and unexpected class of phosphinyloxysulfonates via a novel rearrangement process (Eq. 1). 

NMR spectra). Attempts to degrade 74 to the chlorophin 76 were not successful. Oxidation of 72 with m-chloroperoxybenzoic acid (MCPBA) gave the lactam 77 (84CC920). 

The following examples use m-chloroperoxybenzoic acid (MCPBA), a common epoxidizing reagent, to convert alkenes to epoxides having the same cis or trans stereochemistry. MCPBA is used for its desirable solubility properties The peroxyacid dissolves, then the spent acid precipitates out of solution. 

The conversion of alkenes to epoxides is covered in most introductory organic chemistry texts, often exemplified by the use of m-chloroperoxybenzoic acid (MCPBA) as the epoxidizing reagent. Bradley et al. compared the enantioselective Sharpless epoxidation of geraniol with the classical MCPBA method, which gives a racemic product 21). Hoye and Jeffrey have illustrated a... 

The reaction of alkenes with peroxy acids provides for convenient and selective oxidation of double bonds. The peroxy acids most commonly used in the laboratory are m-chloroperoxybenzoic acid (mCPBA), monoperoxyphthalic acid magnesium salt (MMPP), peroxybenzoic acid, peroxyformic acid, peroxyacetic acid, trifluoroper-oxyacetic acid, and 7-butyl hydroperoxide f(CH3)3COOH]. The order of reactivity for... 

The most widely used reagents for conversion of alkenes to epoxides are peroxy-carboxylic acids.m-Chloroperoxybenzoic acid" (MCPBA) is a common reagent. 

A procedure thus far used extensively in the synthesis of biological phosphates has now been applied at a more fundamental level. When acted upon by an alcohol R OH in the presence of l//-tetrazole, the cyclic phosphoramidite (3) yields the P(III) ester (4). Oxidation of the latter with m-chloroperoxybenzoic acid (mCPBA) then affords the cyclic... 

A modification of this method consists of the oxidative diacetoxylation of iodoarenes in acetic or trifluoroacetic acid using appropriate oxidants, such as periodates [149-151], chromium(VI) oxide [152], sodium percarbonate [153], m-chloroperoxybenzoic acid (mCPBA) [130, 154-158], potassium peroxodisulfate [159,160], HaOa-urea [161], Selectfluor [33] and sodium perborate [132]. The oxidation of iodoarenes with sodium perborate in acetic acid at 40 °C is probably the most general procedure that has been used for the small-scale preparation of numerous (diacetoxyiodo)-substituted arenes and hetarenes (Scheme 2.14) [132,133,162-166]. For example, the chiral diacetate 31 and several analogous... 

Alkylcarboxamides can be converted into the respective amines by Hofinann rearrangement using hypervalent iodine species generated in situ from iodobenzene and a terminal oxidant, such as Oxone (2KHSO5 KHSO4 K2SO4) or m-chloroperoxybenzoic acid (mCPBA). In particular, a convenient experimental procedure for the preparation of alkylcarbamates using Oxone as the oxidant in the presence of iodobenzene in methanol (Scheme 3.166) has been developed [359]. 

In 2005 Ochiai and coworkers reported the first iodobenzene-catalyzed reaction, a catalytic variant of a-acetoxylation of ketones based on the in situ generation of (diacetoxyiodo)benzene from iodobenzene using m-chloroperoxybenzoic acid (mCPBA) as a terminal oxidant [3]. In a typical example, the oxidation of a ketone with mCPBA (2 equiv) in acetic acid in the presence of a catalytic amount of iodobenzene (0.1 equiv), BF3 -OEt2 (3 equiv) and water (5 equiv) at room temperature under argon affords the respective a-acetoxy-ketone 1 in a moderate yield (Scheme 4.1). 4-Iodotoluene and 4-chloroiodobenzene can also serve as catalysts in the a-acetoxylation of ketones under these reaction conditions however, the use of iodobenzene results in the highest yields [3]. The use of at least 10 mol% iodobenzene in this reaction is necessary. When smaller amounts are used, the reaction slows and Baeyer-Villiger oxidation products resulting from a direct reaction of mCPBA and the ketone are observed [3],... 

Recyclable (diacetoxyiodo)arenes 65, 69, 73 and 76 (Figure 5.3) are prepared in excellent yields by the oxidation of appropriate iodides 64, 68, 72 and 75 using m-chloroperoxybenzoic acid (mCPBA) in acetic acid [74-76]. The diacetates 65 and 69 can be subsequently converted into the respective... 

Lesquerella oil has been epoxidized by traditional methods (30) on a laboratory scale with m-chloroperoxybenzoic acid (MCPBA) as outlined in Scheme 9. Reactions were performed below 25°C wifli a 10% excess of MCPBA to provide an 86% theoretical yield of epoxidized lesquerella oil, which has an oxirane content of 4.95%. 

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