Epoxide ethylene oxide

Alkylation reactions reveal a mechanistic aspect of the cuprate reactions different from that of addition reactions. Theoretical analyses of reactions of alkyl halides (Mel and MeBr) [123, 124] and epoxides (ethylene oxide and cyclohexene oxide) [124] with lithium cuprate clusters (Me2CuLi dimer or Me2CuLi-LiCl, Scheme 10.11) resolved long-standing questions on the mechanism of the alkylation reaction. Density functional calculations showed that the rate-determining step of the... 

Hardin BD, Niemeier RW, Sikov MR, et al Reproductive-toxicologic assessment of the epoxides ethylene oxide, propylene oxide, butylene oxide, and styrene oxide. Stand J Work Environ Health 9 94—102, 1983... 

Alkenes undergo a number of oxidation reactions in which the C=C is oxidized. The simplest epoxide, ethylene oxide, is prepared hy catalytic oxidation of ethylene with Ag at high temperatures (250 °C). 

Epoxides are important intermediates in many industrial processes. For example, the reaction of the simplest epoxide, ethylene oxide, with water is employed to produce ethylene glycol, which is used in antifreeze and to prepare polymers such as Dacron. One method for the preparation of ethylene oxide employs an intramolecular nucleophilic substitution reaction of ethylene chlorohydrin ... 

Amines can also open epoxides. Ethylene oxide reacts with aqueous ammonia to give ethanolamine, an important industrial reagent. The nitrogen atom in ethanolamine is still nucleophilic, and ethanolamine can react further to give diethanolamine and triethanolamine. Good yields of ethanolamine are achieved by using excess ammonia. 

Preparation of an alcohol from an epoxide is shown below. The epoxide (ethylene oxide) ring opens when the nucleophile attacks the carbon-oxygen bond. Note the fact that the nucleophilic carbon is supplied by the Grignard reagent (methyl magnesium bromide). 

Scheme 8.96. The extension of a carbon chain by two carbon atoms as a consequence of the ring opening of an oxirane (epoxide, ethylene oxide) by the reaction with a representation of an organometallic reagent (benzylmagnesium bromide, a Grignard reagent), hydrolysis, and conversion of the resulting alcohol (3-phenyl-l-propanol) to the corresponding alkyl bromide (l-bromo-3-phenylpropane).

Oligoalkylene glycols (OAGs) are produced hy addition of epoxides (ethylene oxide, propylene oxide, butylene oxide) to a starting molecule. All the epoxides described can be converted to polymeric substances by opening the ring. Alkali is generally used as catalyst for this reason ... 

---