Ethylene-l,2-diols

The preparation of enols of simple aldehydes and ketones has been achieved by rDA reactions under FVP conditions. Equation (17) illustrates the formation of enols by this method. The percentage of enol reported shows that the enols of aldehydes appear to be isolated more readily than those of the ketones. The last two entries are preparations of the simplest enediols, ( )- and (Z)-ethylene-l,2-diols. A very similar process was used to unmask the protected ethylene cycloadduct (23) and produce 2-hydroxybu-tadiene (24), an elusive enol form of the more stable unsaturated ketone, as given by equation (18). ... 

Phosphorus trihromidefcuprous bromide-zinc 1,3-Dienes from 3-ethylene-l,2-diols... 

The inherent chemistry above is not altered by substituting the phenyl rings of the ketone or pinacol with methyl groups. The ketone 4,4 -dimethylbenzophenone, as well as the pinacol 1,2,2-tetrakis-(4-methylphenyl)ethane-l,2-diol (TBP) react with U giving tetrakis-(4-methylphenyl)ethylene and l,l, ,2-tetrakis(4-methylphenyl)ethane. A lsl mixture of benzophenone and 4,4-dimethylbenzophenone gives the six expected coupling products. 

Alcohols that have one OH in a molecule are termed mono-hydric alcohols. Those with two OH groups are called di-hydric alcohols. The compound we use as antifreeze for cooling systems in car engines is such a compound, ethan-l,2-diol (the older name is ethylene glycol Figure 3.3). 

Acid-catalyzed hydrolysis of isobutylene oxide (8) is >750 times faster than that of ethylene oxide (6), and > 99% of the glycol product is from addition of solvent at the tertiary carbon.23 These results are consistent with a mechanism in which there is significant positive charge on the tertiary carbon at the transition state, as discussed in the previous section. Butadiene monoepoxide (10) is slightly less reactive than isobutylene oxide,36 and its acid-catalyzed hydrolysis can potentially proceed via a resonance-stabilized allyl cation (Scheme 6). However, the acid-catalyzed hydrolysis of 10 yields 96% of 3-buten-l,2-diol (15) and only 4% of 2-butene-1,4-diol (16),36 and the acid-catalyzed methanolysis of 10 is reported to yield only 2-methoxy-3-buten-l-ol.37 An A-2 mechanism proceeding via transition state 17 may account for the observation that 1,2-diol 15 is the predominant product from acid-catalyzed hydrolysis of 10. The minor yield of the 1,4-diol 16 may be formed from reaction of... 

Terylene/te-ra-leen/(Tradewari ) A polymer made by condensing benzene-1,4-di-carboxylic acid (terephthalic acid) and ethane-l,2-diol (ethylene glycol), used for making fibers for textiles. 

Thermodynamic inhibitors are chemicals such as methanol or ethylene glycol (ethane-l,2-diol). These materials shift the hydrate formation phase boundary away from fhe femperafure and pressure conditions of fhe gas-fransportation process by increasing the driving force required for fhe formation. Thermodynamic inhibitors are used at very high concentrations, as much as 60 % methanol can be used in deep water extractions, which proves to be a very costly way of preventing the build-up of hydrates. 

The most generally useful polyester is that made by reaction between dimethyl terephthalate (dimethyl henzene-l,4-dicarboxylate) and ethylene glycol (ethane-l,2-diol). The product is used under the trade name Dacron to make clothing fiber and tire cord, and under the name Mylar to make recording tape. The tensile strength of poly(ethylene terephthalate) film is nearly equal to that of steel. 

C4H10O2 110-80-5 2-Ethoxyethanol syn. Cellosolve Ethane-l,2-diol ethyl ether nEthyl Cellosolve 3-Oxapentan-l- Ethylene glycol ethyl ether... 

---