Epoxidation and Related Reactions

The double bond in MA and derivatives can be epoxidized to yield epoxysuccinic acid derivatives 92. So far, the primary use of this reaction has been for the synthesis of tartaric acid 93 (R = H). Epoxysuccinic acid can also be made by the hypochlorite reaction of maleic acid. The final product, dl-trans-a,p-epoxysuccinic acid 92 (R = H) is isolated in a 75% yield. 

Recently, there has been renewed activity in this area. Saotome et (111,112) Korl, and Wagner and Schafer. have used 

Since two optically active centers are created during the reaction, besides the d and / forms, a meso form is possible. This form has no residual optical activity. As was seen earlier, epoxidation of acids or salts yields a mixture of dl isomers. In order to synthesize the tartaric acid, direct hydroxylation of acids or esters is employed. 

The osmium-tetroxide-catalyzed oxidation of olefin is well known. 

The role of osmium tetroxide in cis hydroxylation has been established. A cyclic ester of osmic acid 94 is formed. Hydrolysis produces an Os 

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Via Asymmetric Epoxidation and Related Reactions. Denis et al.35 synthesized the taxol side chain derivative via Sharpless epoxidation. Starting from cw-cinnamyl alcohol, the corresponding epoxide compound was prepared with 76-80% ee. Subsequent azide ring opening gives a product that possesses the side chain skeleton (Scheme 7-78). 

Guengerich, F.P. (2003) Cytochrome P450 oxidations in the generation of reactive electrophiles epoxidation and related reactions. Archives of Biochemistry and Biophysics, 409, 59-71. 

The isomorphous substitution of T atoms by other elements produces novel hybrid atom molecular sieves with interesting properties. In the early 1980s, the synthesis of a zeolite material where titanium was included in the MFI framework of silicalite, that is, in the aluminum-free form of ZSM-5, was reported. The name given to the obtained material was titanium silicalite (TS-1) [27], This material was synthesized in a tetrapropylammonium hydroxide (TPAOH) system substantially free of metal cations. A material containing low levels (up to about 2.5 atom %) of titanium substituted into the tetrahedral positions of the MFI framework of silicalite was obtained [28], TS-1 has been shown to be a very good oxidation catalyst, mainly in combination with a peroxide, and is currently in commercial use. It is used in epoxidations and related reactions. TS-1, additionally an active and selective catalyst, is the first genuine Ti-containing microporous crystalline material. 

Jacobsen, E. N., Wu, M. H. Ring opening of epoxides and related reactions. Comprehensive Asymmetric Catalysis i-iii 1999, 3,1309-1326. 

Asymmetric catalysis of epoxide ring-opening reactions 00ACR421. Asymmetric ring opening of epoxides and related reactions 99MI25. 

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