Epoxy compounds preparation

Optically pure (S)-benzyl methyl sulfoxide 139 can be converted to the corresponding a-lithio-derivative, which upon reaction with acetone gave a diastereomeric mixture (15 1) of the /S-hydroxysulfoxide 140. This addition reaction gave preferentially the product in which the configuration of the original carbanion is maintained. By this reaction, an optically active epoxy compound 142 was prepared from the cyclohexanone adduct 141181. Johnson and Schroeck188,189 succeeded in obtaining optically active styrene oxide by recrystallization of the condensation product of (+ )-(S)-n-butyl methyl sulfoxide 143 with benzaldehyde. 

G. C. Fischer. Corrosion inhibitor compositions containing inhibitor prepared from amino substituted pyrazines and epoxy compounds. Patent US 4895702, 1990. 

While dieldrin will, under suitable conditions, exhibit many of the expected reactions of epoxy compounds, it is a remarkably stable oxide. Thus, in its preparation the presence in the oxidizing solution of 1% or more of sulfuric acid in no way affects it. 

Azomethine metal complex pigments replace the metal with tin stabilizers, resulting in a change in shade. In the case of manganese-laked pigments trouble can also be expected in the presence of epoxy compounds. Pigment preparations based on epoxidized soya bean oil are normally used instead of diisodecyl phthalate pastes in the automotive sector e.g. for coloring PVC roofs etc. 

The introduction of epoxidation techniques for polyunsaturated natural oils by Swern and colleagues [7,8] led to industrial interest in the preparation of epoxy compounds useful for resin production [9,10],... 

Even the 1,2-dihydrodiol derivatives of polycyclic aromatic hydrocarbons are converted to the corresponding epoxydiols with MCPBA. The reaction is stereoselective only in some cases. The trans-dihydrodiols (6) give the antiepoxide (7), whereas the cfs-dihydrodiols (8) give a mixture of anti- (9) and syn-epoxy compounds (10). The anti- and syn-diol epoxides of benz[a]anthracene and benzo[a]pyrene have been prepared by this method.10... 

As noted earlier in this section on C-1-substituted compounds, preparation of the epoxy alcohol has been the synthetic objective nearly as often as has been the optically active allylic alcohol. The principles... 

Olefinic compounds are conveniently converted to epoxy compounds by treatment with an organic peracid, commonly perbenzoic acid or peracetic acid in chloroform solution at 0-5°. The preparation of perbenzoic acid has been described. Performic and monoperphthalic acids have also been successfully employed. The reaction has been reviewed. ... 

Epoxy compounds are prepared by heating halohydrins with strong caustic solutions and, where possible, distilling the product as it is formed. By this procedure, 3-chloro-2-butanol yields a mixture of cis-and frans-2,3-epoxybutane (90%), which can be readily separated by fractional distillation. Another example is the conversion of 2-chloro-cyclohexanol to cyclohexene oxide (73%). The reaction is included in an excellent discussion of the chemistry of ethylene and trimethylene oxides, ... 

All the precursors are easily prepared by epoxidation and alkylation of the Diels-Alder adduct of p-benzoquinone and dimethylfulvene, and subsequent pyrolyses of the precursors in a sealed tube under rather mild conditions to yield these epoxy compounds [20-22]. Although there are other methods to prepare such quinone epoxides and a-epoxycyclohexenones, the advantages of the retro Diels-Alder method are as follows 1. epoxidation of quinone adducts proceeds regioselectively to give an epoxide, in which the more substituted double bond in the starting quinone is epoxidized, 2. the adducts are usually stable, and are able to afford appreciably modified quinone moieties, 3. stereoselectivities are expected in the modification of the ewiAj-adducts. 

Accordingly, sodium hydroxide (17% aqueous solution) was stirred with the chlorohydrin ester masterbatch prepared above. The reaction was followed at 40 C using a molar ratio of sodium hydroxide to chlorohydrin ester of 2 1. The reaction was followed by gas chromatography. Fig. 18 shows the rates of conversion of epichlorohydrin and chlorohydrin ester during the reaction. Again, it was shown that after 6.5 hours all the sodium hydroxide had been consumed (cf. sodium hydroxide/sodium carbonate reaction at 40 C) at which time only 64% conversion to the epoxy compound was observed. Correspondingly the epichlorohydrin hydrolysis (25%) had increased in comparison to the sodium hydroxide/sodium carbonate method (15.6% at 40 C). 

Using a procedure similar to the one described for the preparation of the 2p,3P-epoxy compound 40, the known (24S)-configurated A2-6-keto acetonide 6171 was transformed via the bromohydrin 64, deprotection to 65 and HBr elimination, to the (24S)-2p,3P-epoxide 32, which was found to be identical with the native secasterone from Secale cereale (see, Secdon 2). 

It is prepared first by the interaction of o-chlorobenzonitrile and bromo-cyclopentane in the presence of strong alkali to yield an epoxy compound. 

The mediation of 83 to 85 followed by iodination and catalytic hydrogenoly- is gives 87, Compound 86 has been synthesised via controlled mediation or tosy-lation at the 3 -position, iodination and reduction. A patent from Megi describes the conversion of the 3 -to l derivative into the 3, 4 epoxy compound and the catalytic reduction to 86. 3 -Epi-4 -deoxyneamine, 88. is prepared using NaBH4 for the reduction The preparation of 3, 4 -epoxyneamine derivatives 100,... 

The preparation of surfaces to receive epoxy compounds is as important as the selection of the proper system for bonding. Concrete surfaces must be freshly exposed, free of loose and unsound material and should be at proper surface temperatures at the time of epoxy application. Among the methods for preparation of concrete surfaces are sandblasting, mechanical scarification and acid etching. The same procedures may be followed for preparation of steel surfaces. Temperature conditions for epoxy application should be in the range of 50°F. to 90 f. Temperature conditions v ill also affect pot life of mixed compounds, as well as curing time. 

Silicon-containing epoxides with hydrolytically stable carbon-silicon bonds were first prepared by Pleuddeman by the addition of hydrogen functional silanes to epoxy compounds containing double bonds (7,8). We have employed this reaction extensively to prepare several different difunctional epoxy monomers as shown in Table I. An example of this reaction is given in equation 1 for the preparation of difunctional monomer HI. 

Compounds which contain epoxy groups in the cycloaliphatic ring as well as in the pendant glycidyl (i.e. 2,3-epoxypropyl) groups, so-called aliphatic-cycloaliphatic epoxy compounds (ACECs), have been less known. The methods of industrial synthesis of ACECs and the future areas of application were scarcely described until the first articles appeared in the 1970s [4]. Then many new ACECs were prepared and the methods of preparation were described. The syntheses were followed by the investigation of the properties of crosslinked ACECs and the consideration of possible applications. 

There is very little information about halogenated aliphatic and cycloaliphatic epoxy compounds. Brominated epoxy compounds were prepared by the addition of Br to the cyclohexenyl double bond in a diglycidyl ether in mild conditions (Scheme 60) [39]. 

Composites Prepared from Cycloaliphatic and Aliphatic-Cydoaliphatic Epoxy Compounds Crosslinked with Phenol-Formaldehyde Oligomers... 

S. K. Ihm, C. G. Oh, J. H. Ahn, J. C. Kim, and D. C. Sherrington. Poly-imide-supported transition metal complex catalyst and process for preparing epoxy compounds using the same. US Patent 6063 943, assigned to Korea Advanced Institute of Science and Technology (KR), May 16,2000. 

Halohydrins Halogen compounds that contain a halogen atom (s) and a hydroxy (OH) group (s) attached to a carbon chain or ring. Can be prepared by reaction of halogens with alkenes in the presence of water or by reaction of halogens with triols. Halohydrins can be easily dehy-drochlorinated in the presence of a base to give an epoxy compound. 

Hergenrother et al. have calculated the flaming combustion efficiency of epoxy resins prepared from various epo>y- or amine-functional organo-phosphorus compounds by dividing the EHC measured in fire calorimetiy tests (Ohio State University apparatus and cone) by the effective heat of complete combustion measured in a PCFC. The combustion efficiency ranged roughly from 0.6 to 0.8 versus 0.7 for the phosphorus-free epo)y resin) whatever the oxidation state of phosphorus and other parameters. The authors concluded that there is no discernible effect [...] on the combustion efficiency in the flame . 

Natural and synthetic rubber and synthetic resins are soluble in organic solvents resulting in cements, resin solutions, or lacquers. In addition, there are many cellulose derivatives, such as nitrocellulose, ethyl cellulose, and cellulose acetate butyrate, used in preparing solvent-based adhesives. Solvent-hased adhesives are also prepared from cyclized rubber, polyamide, and polyisobutylene. Low-molecular-weight polyurethane and epoxy compounds can be used with or without solvent. On the other hand, high-molecular-weight types or prepolymers require solvent to make application possible. 

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