Ethylene oxide , ring-opening

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). 

Obtained by the ethylene oxide ring-opening polymerization using Friedel-Crafts catalysts such as boron trifluoride, tin tetrachloride or zinc chloride, or acid or alkali catalysts. 

Ethylene oxide Ring-opening polymerization Molecular weights 200 to 600— surfactants, humectants, lubricants Molecular weights >600 pharmaceutical and cosmetic bases, lubricants, mold release agents Molecular weights 10 to 5 X10 — water-soluble packaging films and capsules... 

Opening of the ethylene oxide ring occurred immediately upon adding catalyst. 

In opening the ethylene oxide ring of the methyl anhydroalloside... 

It is of interest to note that the second product to be expected from the addition of ammonia to the anhydromannoside (XLVI), by opening the ethylene oxide ring at carbon atom 2, would be methyl 2-amino-/3-D-glucoside (XLIX). In order to decide whether chitosamine (glucosamine) has a 2-arainoglucose or 2-aminomannose configuration, Haworth,... 

Myers and Robertson, and Robertson, Myers and Tetlow, have reported a synthesis of methyl epiglucosamine starting with methyl 2,3-anhydro-4,6-benzylidene-a-D-mannoside (XLIII). By opening the ethylene oxide ring with ammonia they obtained a crystalline product, of m. p. 188° and - -88.9° in chloroform, which was a mixture of... 

Cleavage of oxides and ethers. The epoxide ring of ethylene oxide is opened... 

Ozone dimethyl sulfide Oxidative ring opening Diacetals from cyclic ethylene derivs. 

On the other hand, acetylation with acetic anhydride in the presence of anhydrous ferric chloride or zinc chloride apparently involves an opening of the ethylene oxide ring at the tertiary carbon with consequent inversion, for the hydroxy derivative ultimately obtained is not hydroxyisomytilitol. Hence, it would seem to be the epimer configurationally related to mytili-tol. 

The product in this case is called ethylene oxide, and is an important monomer and reactive intermediate. A catalyst RXM (not specified here) can open the ethylene oxide ring, which then adds to itself to form polyethylene glycol (PEG) ... 

Ozone/sodium tetrahydridohorate Diols by oxidative ring opening of cyclic ethylene derivatives via a-hydroxy-a -alkoxyperoxides Retention of carboxyl groups... 

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