Ethane diol

Diol Components. Ethylene glycol (ethane 1,2-diol) is made from ethylene by direct air oxidation to ethylene oxide and ring opening with water to give 1,2-diol (40) (see Glycols). Butane-1,4-diol is stiU made by the Reppe process acetylene reacts with formaldehyde in the presence of catalyst to give 2-butyne-l,4-diol which is hydrogenated to butanediol (see Acetylene-DERIVED chemicals). The ethynylation step depends on a special cuprous... 

The initial investigation focused on the use of threitol-derived auxiliaries with various substituent groups on the dioxolane ring (Table 3.3). However, it became evident that the oxygen atoms in the substituents had a detrimental effect on selectivity. Comparison of the diastereoselectivities for the ketals 69-71, which contain Lewis basic sites in the substituents at the 1 and 2 positions, with those from simpler diol derived ketals 72-74 demonstrates the conflicting effects of numerous coordination sites. The simpler, diol-derived ketals provide superior results compared to the threitol derived ketals. The highest diastereoselectivity is observed in the case of the 1,2-diphenyl ethane-1,2-diol derived ketal 74. 

Aqueous solutions of many salts, of the common strong acids (hydrochloric, nitric and sulphuric), and of bases such as sodium hydroxide and potassium hydroxide are good conductors of electricity, whereas pure water shows only a very poor conducting capability. The above solutes are therefore termed electrolytes. On the other hand, certain solutes, for example ethane-1,2-diol (ethylene glycol) which is used as antifreeze , produce solutions which show a conducting capability only little different from that of water such solutes are referred to as non-electrolytes. Most reactions of analytical importance occurring in aqueous solution involve electrolytes, and it is necessary to consider the nature of such solutions. 

Whilst some organic compounds can be investigated in aqueous solution, it is frequently necessary to add an organic solvent to improve the solubility suitable water-miscible solvents include ethanol, methanol, ethane-1,2-diol, dioxan, acetonitrile and acetic (ethanoic) acid. In some cases a purely organic solvent must be used and anhydrous materials such as acetic acid, formamide and diethylamine have been employed suitable supporting electrolytes in these solvents include lithium perchlorate and tetra-alkylammonium salts R4NX (R = ethyl or butyl X = iodide or perchlorate). 

Much more difficult is the interpretation of the behaviour of supported catalysts in the ethane-1,2-diol oxidation. In fact, despite the smaller gold particles, Au/XC72R displayed the worst performance either considering the 2 g preparation or the larger preparations (Table 14). 

Fig. 12.1 Typical chromatogram containing A, acetonitrile B, 2-chloroethanol C, 4ng of 2 bromoethanol D, ethane-1,2-diol E, 2-iodoethanol F, acetamide Q unknown and H, 2,2 -dihydroxydiethyl ether.

The reaction appears to be general and the additions are regiospecific and stereoselective. The product from the reaction with 2-propanol has been used for the synthesis of cis-chrysanthemic acid,8 and the product with methanol has been used for the construction of novel 2, 3 -dideoxy-3 -hydroxymethylnucleosides.9 In addition, ethane-1,2-diol provides the expected photoadduct as a 1 1 mixture of the two possible diastereoisomers, and these can be easily separated as their acetonides, to provide compounds with three contiguous chiral centers emanating from furan-ones with only one chiral center.9 More recently, we have shown that photoinduced-... 

Recently, a large anionic pigment has been intercalated into an LDH host by ion-exchange of an Mg/Al LDH nitrate precursor with a solution of C.I. Pigment Red 48 2 (the calcium salt of 4-((5-chloro-4-methyl-2-sulfophenyl)azo)-3-hydroxy-2-naphthalene-carboxylic acid), in ethane-1,2-diol [215]. The UV-visible diffuse reflectance spectra of C.I. Pigment Red... 

The effect of pH on the periodate oxidation of seven anilines has been investigated. " The kinetics of periodate oxidation of aromatic amines have been studied. " - " Periodate oxidation of oxalic acid is catalysed by Mn(II). " The reaction of ethane-1,2-diol with periodate has been investigated under a variety of conditions and the results compared with those of earlier work and analogous studies on pinacol. " The 104 ion is the primary reactant, with H5IO6 as a secondary reactant the reverse is true for pinacol. The complex observed in previous work is shown not to be an intermediate, but rather to deactivate the reactants. 

The enolate reactivity associated with this approach to C-glycoside synthesis was, however, first developed with octulosonic acid derivatives, such as 283 [114], 284 [115], and 285 [116], and a series of examples involving aldehyde and halide-based electrophiles are shown in Scheme 74. Related studies involving stereoselective protonation of this class of exocyclic enolate have also been described [13] and Scheme 75 illustrates this with an example of reductive samariation (using ethane-1,2-diol, but no HMPA) of an anomeric acetate 286 [117]. 

The 6,7-dihydro-5/f -1,4-dioxepin (266) has been prepared (54CR(38)982). and more recently it has been shown that the 2,3-dihydro-5jF/-l,4-dioxepins (263) and (265) can be produced from 1,4-dioxine-halocarbene adducts (264), either by heating under reflux in xylene or by treatment with bases. The allylic chlorine atom in (263) is readily substituted by alkoxide or cyanide ions (77ZC331, 76UKZ968). Saturated rings of type (267) have been prepared by the treatment of cyclic acetals of ethane-1,2-diol with vinyl ethers in the presence of boron trifluoride, and l,4-dioxepan-5-one (268) has been prepared by the reaction of bromoform and silver nitrate with aqueous dioxane (60AG415). 

Side products phenyl ethane-1,2-diol and benzaldehyde. 

Ethylene glycol (ethane-1,2-diol), a major component of antifreeze, is readily metabolized by many organisms that have the glyoxylate cycle. Can you propose a sequence of catabolic steps that can explain the catabolism of ethylene glycol ... 

Keywords aldehyde, ethane-1,2-diol, Si02-NaHS04, microwave irradiation, acetalization, acetal... 

Aldehyde (5 mmol), ethane 1,2-diol (5 mmol) and metal sulfate (5 mmol) supported on silica gel (1.65 g) were mixed in a Pyrex test tube and subjected to microwave irradiation for 36 min. After complete conversion, as indicated by TLC, the reaction mass was charged directly on small silica gel column (100-200 mesh) and eluted with ethylacetate-hexane (2 8) to afford pure acetal in 80-98% yield. 

A mixture of benzaldehyde (1.06 g, 10 mmol), ethane-1,2-diol (0.62 g, 10 mmol) and commercial grade cadmium iodide (1.85 g, 5 mmol) were thoroughly mixed at room temperature in an Erlenmeyer flask and placed in a commercial micro-wave oven operating at 2450 MHz frequency. After irradiation of the mixture for 1.5 min (monitored vide TLC) it was cooled to room temperature, extracted with dichloromethane, washed with sodium thiosulfate and dried over anhydrous Na2S04- Evaporation of the solvent gave almost pure products and there was no evidence for the formation of any hydroxy ester or iodoester. Further purification was achieved by column chromatography on silica gel using 1 5 chloroform-petroleum ether as eluent. 

The catalytic performance of Nafion SAC-13 in the formation of 1,1-diacetates,677 in turn, is very similar to that of HBF4-silica. In the acetalization of carbonyl compounds with ethane-1,2-diol and propane-1,3-diol, products are isolated in good to excellent yields. The formation of THP ethers of alcohols is fast and protected alcohols are isolated in high yields [Eq. (5.238)]. Nafion SAC-13 can also be used in the removal of the THP ether group677 although the transformation requires somewhat longer reaction times (30 min-6 h, 81-97% yield). Furthermore, the catalyst could be recycled in all three processes with practically no loss of activity. 

We can obtain different polymers with different properties if we carry out condensation polymerisation reactions between other monomer molecules. For example, if we react ethane- 1,2-diol with benzene-1,4-dicarboxylic acid, then we produce a polymer called Terylene. 

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