Diether compound

In the presence of an excess of potassium ethoxide, the ethoxide anion joins the less negative end of the double bond. Strong electron back-donating power of fluorine increases negativity at the carbon linked to chlorine and causes the addition of the ethoxide ion to the carbon linked to fluorine. Subsequent ejection of fluoride anion restores the double bond, and the final product is a diether, compound P [7/J. 

Ans. Compound I is a hemiacetal, compound II is something else (ether-alcohol), compound III is a hemiketal, compound IV is something else (diether), compound V is something else (alcohol-ketone). 

To recap, there are two types of donors, internal and external. For the third-generation catalysts the internal/external pair is an ester/ester pair, while for the fourth-generation it is the phthalate/alkoxy silane pair. The fifth-generation Ziegler-Natta catalysts are comprised of an internal donor, which is a diether compound and may be used with or without the additional external donor (see Table 9). 

Kreussler patented use of diether compounds, which are considered to have low toxicity, for drycleaning of textiles, leather, and furs. Impregnation of textiles is used before printing to prevent bleeding of inkjet ink. Solvent used for impregnating solution is water or alcohol capable to dissolve organic acid. ... 

Many substances have more than one ether linkage Two such compounds often used as solvents are the diethers 1 2 dimethoxyethane and 1 4 dioxane Diglyme also a commonly used solvent is a triether... 

Magnesium iodide is soluble in alcohols and many other organic solvents, and forms numerous addition compounds with alcohols, ethers, aldehydes, esters, and amines. One example is magnesium iodide dietherate [29964-67-8], Mgl2 prepared by gradual addition of iodine to a... 

The mem-dichlorobenzene complex reacts with protected 0-aryltyrosines to give aryl ethers. Both chlorine atoms can be sequentially substituted to give symmetrical or disymmetrical triaryl diethers (Scheme XVI). The building up of such diaryl ethers from phenolic compounds which have amino groups in their side chains... 

List B contains all compounds that form peroxides which become dangerous when they reach a critical concentration. The danger will often become apparent during distillation operations. For hydrocarbons, this is the case for deca- and tetrahydronaphthalene, cyclohexene, dicyclopentadiene, propyne and butadiene. S ondary alcohols such as 2-butanol also form part of this list. Finally, for ethers there are diethyl ethers, ethyl and vinyl ethers, tetrahydrofuran, 1,4-dioxan, ethylene glycol diethers and monoethers. 

An organic sulfur compound containing an acetal function had been oxidised to the sulfone with 30% hydrogen peroxide in acetic acid. After the liquor had been concentrated by vacuum distillation at 50-60°C, the residue exploded during handling. This was attributed to formation of the peroxide of the acetal (formally a gem-diether) or of the aldehyde formed by hydrolysis, but formation and explosion of peracetic acid seems a more likely explanation. 

Among the various derivatives of biomass, furanic compounds obtained from furfural are important (200,0001 year-1). A new family of furanic diethers has been obtained by alkylation of 2,5-furandimethanol or furfuryl alcohol under microwave irradiation with PTC solvent-free conditions [83] (Scheme 8.59). 

Phospholipids are also found which have similar structures (Table 12.6). These include lysophospholipids, which have only one of the two possible positions of glycerol esterified, almost invariably at carbon 1, and the plas-malogens, in which there is a long chain vinyl ether at carbon 1 instead of a fatty acid ester. These compounds also contain an amino alcohol, which may be either serine, ethanolamine or choline. Other rarer phospholipids are the monoacyl monoether, the diether and the phosphono forms. 

To understand and comparev the mechanisms and rates of polyester formation in catalyzed copolymerization, processes taking place in the system epoxide-anhydride without any initiator are described. In this review, copolymerization in the absence of compounds that do not occur in the initial reaction mixture is regarded as a non-catalyzed reaction. This means that the presence of alcohols, phenols or acids is not excluded. These compounds may be considered as copolymerization catalysts however, because of their possible occurrence in the polymerization system they are not regarded as initiators. The presence of OH groups in epoxy compounds, especially in resins where they occur as chlorohydrines (I), monoethers (II), and diethers of glycerol (III)... 

The ester enolate-imine condensation, also called Gilman-Speeter reaction, is another well-accepted method for (3-lactam synthesis (Scheme 4) [67-69]. In 1997, Tomioka reported the first example of a direct catalytic enantioselective synthesis of (3-lactam by using this method [70]. The active reagent is a ternary complex (comprising LDA, the ester enolate, and tridentate amino diether), which finally affords the (3-lactam compounds in high yields and good ee values. 

Although acetylenic diethers are thermodynamically stable compounds, they show a high kinetic instability that induces polymerization even at low temperatures. ... 

As shown above, di-tert-butoxyethyne 1s the only acetylenic diether prepared so far whose stability allows its use as a synthetic Intermediate. It has been used 1n the synthesis of all the members of the series of monocyclic oxocarbons (deltic, squaric, croconic, and rhodizonic acids), as well as in the synthesis of semisquaric acid, the parent compound of the natural mycotoxins, noniliforndna... 

Otherwise, compound 30, and differently 0-substituted analogues, can be made efficiently from O-protected 2-deoxy nucleosides. Heating thymidine diether 29 in refluxing 1,1,1,3,3,3-hexamethyldisalazene in the presence of ammonium sulfate under an inert atmosphere gives 30 in 47% overall yield from the nucleoside. A notable feature of this approach is that thymidine itself can be converted directly to the unprotected parent of diether 30 with 80% efficiency.26... 

Chelating diethers such as DME and 1,4-dioxane are useful, but their use tends to result in precipitation of a magnesium halide complex this phenomenon is made use of in the most commonly used procedure for obtaining solutions of dialkylmagnesium compounds. 

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