Epoxide from alkenes

Scheme 12.11. Synthesis of Epoxides from Alkenes Using Peroxy Acids...

Figure 4.20 Continuous removal of product by stripping synthesis of epoxides from alkenes applying a batch process with resting cells or a fermenter connected to absorption, extraction and distillation...

The direct catalyzed or uncatalyzed oxidation of alkanes with oxygen is an important reaction in the industrial production of carboxylic acids, hydroperoxides (for production of epoxides from alkenes), alcohols, ketones, or aldehydes [60],... 

It is noticed that when Fe3+OOR is formed in aprotic diluters (under strongly basic conditions) at low temperature, degradation products are synthesized by reaction (7.4) [29], However, in hydroxide diluters oxidants dissociate heterolytically by reaction (7.3) [30, 31], which is proved by the formation of the following products epoxides from alkenes and alcohols from ROOH. 

Both chemical and enzymatic synthetic methods for the asymmetric oxidation of the carbon-carbon double bond have been developed [46], but the area of carbon-carbon double bond oxidations has been shaped by the breakthrough discovery of asymmetric epoxidation of allylic alcohols with the Katsuki-Sharpless method [47]. Catalytic asymmetric synthesis of epoxides from alkenes by Jacobsen... 

Catalysts of this type can be used not only for the enantioseleetive generation of epoxides from alkenes, but also for the hydrolytic kinetic resolution (HKR) of racemic epoxides, particularly the terminal variety. For example, the cobalt(III)salen complex 2 catalyzed the enantioseleetive hydrolysis of racemic hexene oxide 3 in the presence of 0.5 equivalents of water to provide the f/ j-enantiomer in 99% ee. Here, the inorganic ligand was found to be important for catalyst activity and selectivity, with the conventional acetate ligand giving inferior results <03TL5005>. 

Many organisms have been reported to produce epoxides from alkenes with most enantioselec-tivities in the range of 70-100%. The formation of 1,2-epoxyoctane from 1-octene by Pseudomonas aeruginosa in the presence of chloramphenicol has been reported60. It has also been... 

You will see how to make epoxides from alkenes In Chapter 19. 

The most common laboratory method for the synthesis of epoxides from alkenes is oxidation with a peroxycarboxylic acid (a peracid), RCO3H. One peracid used for this purpose is peroxyacetic acid ... 

The peroxy intermediate (1) is an excellent reagent for the synthesis of acid-sensitive benzylic epoxides from alkenes, the oxidation of benzylic CH2 to C=0, and the chemoselective oxidation of alkene sulfoxides to alkene sulfones. It is noteworthy that the reactions are carried out under mild conditions (—35 °C). 

One method for the preparation of epoxides from alkenes involves (1) treating the alkene with chlorine or bromine in water to form a chlorohydrin (or bromohydrin) followed by (2) treating the halohydrin with a base to bring about intramolecular displacement of Cl . These steps convert propene first to l-chloro-2-propanol and then to methyloxirane (propylene oxide). 

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