Hydrogen peroxide in epoxidation

R, R -Tartaric (racemic) acid is obtained synthetically by epoxidation of maleic acid with hydrogen peroxide in the presence of a catalyst followed... 

Nucleophilic opening of oxiranes to give ultimately 1,2-diols is usually effected without isolation of the oxirane oxiranation (epoxidation) of alkenes with unbuffered peroxy-ethanoic acid or hydrogen peroxide in methanoic acid (Section 5.05.4.2.2(/)) tends to give monoesters of 1,2-diols (e.g. 53), which can be hydrolyzed to the diols (Scheme 46). 

Hexafluoroacetone and hydrogen peroxide in buffered aqueous solution can epoxidize alkenes and allylic alcohols.101 N, Af-Dialkylpiperidin-4-one salts are also good catalysts for epoxidation.102 The polar effect of the quaternary nitrogen enhances the... 

Two reagents were investigated as less expensive replacements for MCPBA in the epoxidation of VII (a) 30% hydrogen peroxide in acetic acid at 90-100°C (b) 30% hydrogen peroxide and acetonitrile in ethanol in the presence of potassium bicarbonate (19,20). The first reaction gave a mixture of VIII and an unidentified product. 

Fig. 35 Mechanism of formation of hydrogen peroxide in the Wagnerova Type II photooxygenation of alcohols and its in-situ use to epoxidize alkenes and oxidized sulfides.

In some cases, the pyrrolo[l,2-f]oxazoles were epoxidized with hydrogen peroxide in dichloromethane affording the epoxide with control of stereoselectivity (Equation 52) <1997TA2421, 2000T2437, 2004TA1239>. 

The highly chemo-, regio-, and diastereoselective and stereospecific epoxidation of various allylic alcohols with only 1 equivalent of hydrogen peroxide in water solvent could be efficiently catalyzed by an isolated dinuclear peroxotungstate [W203(02)4(H20)2]2 [93,94] ... 

As a third example for an organocatalytic reaction, based on multiple hydrogen bonding and mechanistically investigated by DFT, we selected olefin epoxidation with hydrogen peroxide in fluorinated alcohol solvents, such as 1,1,1,3,3,3-hex-afluoro-2-propanol (HFIP) (Scheme 8). Here we encounter a new type of catalytic hydrogen bond the cooperative hydrogen bond. 

Scheme 8 Epoxidation of alkenes with hydrogen peroxide in HFIP as solvent...

Fig. 14 Stationary-point structures for the epoxidation of ethene with hydrogen peroxide in the absence and in the presence of one molecule of HFIP, optimized at RB3LYP/6-31+ G(d,p) (selected bond lengths in A RB3LYP/6-311++G(d,p) results in parentheses)...

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