Oxirane, ethane, oxidation

It is widely recognized that Et Zn-H O system is one of the most active catalysts for the stereospecific polymerization of oxiranes. A variety of chemical species are formed in the following way rapid formation of ethylzinc hydroxide, its aggregation, and elimination of ethane to form zinc oxide structure. The maximum catalyst activity was achieved when the mole ratio of zinc to water was one to one, where the predominant formation of a species, Et(ZnO) H, (III), was observed. If we use less amount of water, another species, Et(ZnO) ZnEt, (IV), was also produced concurrently. Contrary to the anionic nature of the former species (III), the latter species (IV) exhibited a cationic nature. For instance, more than 957o of ring cleavage of methyloxirane takes place at O-CH bond with species (III), while the cleavage at 0-CH bond also takes place concurrently with species (IV). 

Oxidations with O2 in SC-CO2 (Scheme 7) also profit from miscibility of gases and high diffusivity. Oxirane and acetaldehyde were obtained by KrF excimer laser irradiation of ethylene and O2 in CO2 under sub- and supercritical conditions. Also ethane and cyclohexane oxidized. [41] The cyclohexane oxidation giving cyclohexanone and cyclohexanol may be greatly manipulated in SC-CO2. [42] Total oxidations in SC-CO2 (to give CO2 and H2O) have been obtained with ethanol,... 

I Synonyms/Trade Names Dimethylene oxide 1,2-Epoxy ethane Oxirane ... 

Ethylene oxide oxirane) and glycol (ethane-, 2-diol)... 

Ethylene oxide dimethylene oxide, dihydrooxirane, oxirane, 1, 2-epoxy ethane, oxacyclopropane, etileno oxido (Spanish), aethyleneoxide (German), oxyde d ethylene (French), ossido dietiline (Italian), oxiraan (Dutch)... 

While all three ring systems are opened by cationic or acid-initiated mechanisms, only the 1,2-epoxide oxirane can be polymerized by both anionic and cationic initiation. Notice that only 1,2-epoxy ethane, ethylene oxide, is derived by epoxidation of an alkene and, thus, is the only alkylene oxide in this series. 

Synonyms Dihydrooxirene Dimelhylene oxide EO Epoxyelhane 1,2-Epoxy-ethane Elhene oxide ETO Oxacycloptepane Orrane Oxidoethane oqfl-Oxido-ethane Oxirane ClassiTication Elher Empirical C2H4O... 

When one of the substituents is a ring, as in 4.23, another method is common. This could be named as cyclohexyl ethyl ether, but can also be described as ethoxycyclohexane. One rather special class of ethers is the epoxides, or oxiranes, such as 4.24 and 4.25. There are two methods by which they can be named—the first refers to the alkene from which they are generally synthesized plus the word oxide. Thus, 4.24 is ethene oxide and 4.25 cyclohexene oxide. Alternatively, the molecule may be named as an alkane, and then the word epoxy, and the location of the three-membered ring added. In this case, the names would be ethane epoxide and cyclohexane-l,2-epoxide. 

---