Epoxidized olefin compounds

Epoxy resins. Most commercially available epoxy resins are based on the diglycidylethers of bisphenol-A, bisphenol-F or other phenolic compounds. A second family of epoxy resins, also used in adhesive formulations, is based on epoxidized olefin compounds such as epoxidized polybutadiene or cycloaliphatic olefins (Fig. Epoxy resins based on the... 

Alcohols 4-(4-Nitrobenzyl)- pyridine Amino compounds, esters and ethers do not interfere, but phenols and acids as well as epoxides, olefins and substances containing labile halogen probably do. [7]... 

New interesting applications have been in the epoxidation of difficult olefin compounds (including hexafluoropropene) with NaOCl, side-chain chlorination of substituted toluenes, diazotization of pentafluoroaniline, polymerization with free radicals, etc. 

Metal alkoxides undergo alkoxide exchange with alcoholic compounds such as alcohols, hydro-xamic acids, and alkyl hydroperoxides. Alkyl hydroperoxides themselves do not epoxidize olefins. However, hydroperoxides coordinated to a metal ion are activated by coordination of the distal oxygen (O2) and undergo epoxidation (Scheme 1). When the olefin is an allylic alcohol, both hydroperoxide and olefin are coordinated to the metal ion and the epoxidation occurs swiftly in an intramolecular manner.22 Thus, the epoxidation of an allylic alcohol proceeds selectively in the presence of an isolated olefin.23,24 In this metal-mediated epoxidation of allylic alcohols, some alkoxide(s) (—OR) do not participate in the epoxidation. Therefore, if such bystander alkoxide(s) are replaced with optically active ones, the epoxidation is expected to be enantioselective. Indeed, Yamada et al.25 and Sharp less et al.26 independently reported the epoxidation of allylic alcohols using Mo02(acac)2 modified with V-methyl-ephedrine and VO (acac)2 modified with an optically active hydroxamic acid as the catalyst, respectively, albeit with modest enantioselectivity. 

Scheme 13.3 Olefinic compounds that form mutagenic epoxides by cytochrome P450 oxidation.

Oesch, F. (1973) Mammalian epoxide hydrases Inducible enzymes catalysing the inactivation of carcinogenic and cytotoxic metabolites derived from aromatic and olefinic compounds. Xenobiotica. 3, 305-340... 

Perbenzoic acid is used for the conversion of olefinic compounds into epoxides. 

Another one-step addition reaction to C=C double bonds that forms three-membered rings is the epoxidation of alkenes with percarboxylic acids (Figure 3.19). Most often, meta-chloroperbenzoic acid (MCPBA) is used for epoxidations. Magnesium monoperoxyphthalate (MMPP) has become an alternative. Imidopercarboxylic acids are used to epoxidize olefins as well. Their use (for this purpose) is mandatory when the substrate contains a ketonic C=0 double bond in addition to the C=C double bond. In compounds of this type, percarboxylic acids preferentially cause a Baeyer-Villiger oxidation of the ketone (see Section 14.4.2), whereas imidopercarboxylic acids selectively effect epoxidations (for an example see Figure 14.35). 

Aliphatic and Cycloaliphatic Resins. Aliphatic and cycloaliphatic epoxy resins have been produced from the epoxidation of olefinic compounds. The epoxidation process involves the use of an olefinic or polyolefinic compound and a peracid (e.g., peracetic acid) or other... 

Perbenzoic acid is used for the conversion of olefinic compounds into epoxides. y= + Ph-CO-02H ------------ Qr + Ph COjH... 

Figure 3.18 Epoxidation of olefinic compounds with dimethyldioxirane.

Perbenzoic acid is an important reagent for the preparation of epoxides from olefinic compounds (method 126). When the epoxides are unstable in aqueous solution, glycols ate formed directly. The over-all reaction results in trans addition of hydrcscy groups to the double bond for crotonic and isocrotonic acids. ... 

A recent attempt to repeat the rearrangement of the 3a-acetoxy 5a, 6a-epoxide (so) to obtain the 5)S-6-ketone gave instead a mixture of six products, with the 6-ketone only as a minor constituent [6a]. The major products were the and A8(i4).olefinic compounds... 

Chromic acid oxidation of olefins can rarely be used for the preparation of oxiranes because they occur as intermediates that rapidly undergo further transformation. From an investigation of the mechanism of oxidation of triaryl-substituted olefins, it was concluded that a carbonium ion or cyclic chromate ester is a possible intermediate. Selective epoxidation of compounds containing conjugated double bonds is attainable by means of chromic-acid oxidation (Eq. 48) 535 Exclusively cis product was obtained from a highly substituted octalin with Na2Cr04, KMn04, or ozone (Eq. 49). ... 

C. Neri, B. Anfossi, A. Esposito, F. Buonomo, Process for the epoxidation of olefinic compounds, European Patent EP 100119, July 13,1983, To ANIC, S.p.A. 

The results of recent investigations S of model systems provide compelling evidence that stabilized atomic oxygen is present in Compound I and Compound II of horseradish peroxidase. Thus, the combination of tetrakis(2,6-dichlorophenyl)-porphinato-iron(ni) perchlorate (6, Scheme 4-4) with pentafluoro-iodosobenzene, zn-chloroperbenzoic add, or ozone in acetonitrile at -35°C yields a green porphyrin-oxene adduct (7). This species, which has been characterized by spectroscopic, magnetic, and electrochemical methods, cleanly and stereospecifically epoxidizes olefins (>99% exo-norbornene-oxide). 

Group Vin metals are well established oxidising agents for the functionalisation of olefinic compounds. Ruthenium and osmium catalysts promote the oxidative cleavage of the double bond in olefinic compounds to aldehydes or ketones which may undergo further reaction to form carboxylic acids in some cases. However selective epoxidation is influenced by the nature of the ligands which... 

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