Ethyl-vinyl ether

The two doublets of doublets at 4.15 and 3.96 ppm (Fig. 8.23c) must be coupled to one another because they both have the coupling constant of 1.9 Hz in common. This geminal coupling constant is typical of the terminal methylene of an alkene. 

Solubility sol all common organic solvents slightly sol water. Form Supplied in ethyl vinyl ether and n-butyl vinyl ether are colorless, extremely flammable liquids, while methyl vinyl ether is a colorless, extremely flammable gas. Ethyl vinyl ether is supplied stabilized with triethanolamine and methyl vinyl ether is supplied in stainless steel cylinders. 

Purification ethyl vinyl ether and n-butyl vinyl ether may be distilled from K2CX 3 or Na if puriflcation of the commercial materials is desirable. 

Handling, Storage, and Precautions all three compounds react violently with halogens and with strong oxidizing agents, and undergo rapid polymerization in the presence of acids. These 

Augmenting its role as a protecting group, the EE group has been used to direct ort/io-lithiation in suitably substituted aromatic ethers, yielding lithiated species that react rapidly with a variety of electrophiles, such as Carbon Dioxide, to give the phthalide (eq 7).  

Acetal Condensations. The acid-catalyzed condensation of ethyl vinyl ether with acetals derived from a,p-unsaturated aldehydes and ketones is an excellent method to lengthen a carbon chain by two carbon atoms, particularly of polyenals. In an industrial process for the manufacture of the Cie aldehyde (eq 13), the C14 acetal is reacted with ethyl vinyl ether in the presence of Zinc Chloride to give an alkoxy acetal, which, without isolation, is then hydrolyzed with moist acetic acid. Longer conjugated carotenals have been synthesized by this method, and montmo-rillonite K-10 clay (see MontmoriUonite KIO) has been reported to be an excellent replacement for the Lewis acids normally used in the condensation.  

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Apparatus 250-ml round-bottomed flask for the cleavage of THF 500 ml flask (see Fig. 1) for the coupling with ethyl vinyl ether 1-1 flask (see Fig. 1) for the reaction with allenyl1ithiurn 500-ml round-bottomed flask for the deprotection. 

Hate 1. This excess was used to be absolutely sure that all a-chloroether would have reacted. Traces of this compound, if still present in the reaction mixture, will hydrolyse during the aqueous work up. The acid that is liberated can cause hydrolysis of the product to H2C=CH-C(=0)CH(CH3)0C2H5. HoLp. A. Prepared by introducing 0.30 mol of dry gaseous HCl (weight increase) into 45 ml of freshly distilled ethyl vinyl ether (excess) at -30°C. 

In connection with mechanistic studies on the Wacker reaction, the transmetallation of ri-ethoxy- and /3-hydroxyethylmercury(II) chloride with PdCB has been carried out, giving ethyl vinyl ether and acetaldehyde[366]. The reaction proceeds by the formation of ri-ethoxy- and /3-hydroxyethylpalladium chlorides (401), which decompose as soon as they are formed. 

Vinyl Ethers. The principal commercial vinyl ethers are methyl vinyl ether (methoxyethene, C H O) [107-25-5], ethyl vinyl ether (ethoxyethene, C HgO) [104-92-2], and butyl vinyl ether (1-ethenyloxybutane, C H 20) [111-34-2]. (See Table 8 for physical properties.) Others such as the isopropyl, isobutyl, hydroxybutyl, decyl, hexadecyl, and octadecyl ethers, as well as the divinyl ethers of butanediol and of triethylene glycol, have been offered as development chemicals (see Ethers). 

Ethyl vinyl ether was the first to be prepared, in 1878, by treatment of diethyl chloroacetal with sodium (216). Methyl vinyl ether was first Hsted in Reppe patents on vinylation in 1929 and 1930 (210,211). 

Shipment, Stora.ge, ndPrices. Methyl vinyl ether is available in tank cars or cylinders, while the other vinyl ethers are available in tank cars, tank wagons, or dmms. Mild steel, stainless steel, and phenoHc-coated steel are suitable for shipment and storage. If protected from air, moisture, and acidic contamination, vinyl ethers are stable for years. United States bulk prices in 1991 for methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether were listed as about 5.78/kg, 6.28/kg, and 6.08/kg, respectively. 

Specifications and Analytical Methods. Vinyl ethers are usually specified as 98% minimum purity, as determined by gas chromatography. The principal impurities are the parent alcohols, limited to 1.0% maximum for methyl vinyl ether and 0.5% maximum for ethyl vinyl ether. Water (by Kad-Fischer titration) ranges from 0.1% maximum for methyl vinyl ether to 0.5% maximum for ethyl vinyl ether. Acetaldehyde ranges from 0.1% maximum in ethyl vinyl ether to 0.5% maximum in butyl vinyl ether. 

A number of inhalation anesthetics have been introduced to clinical practice, some of which are Hsted in Table 1. AH agents introduced after 1950, except ethyl vinyl ether, contain fluorine. Agents such as ether, chloroform, trichloroethylene (Tdlene), cyclopropane, and fluoroxene (Fluoromar), which were once used, have been displaced by the newer fluorinated anesthetics. 

The observation in 1949 (4) that isobutyl vinyl ether (IBVE) can be polymerized with stereoregularity ushered in the stereochemical study of polymers, eventually leading to the development of stereoregular polypropylene. In fact, vinyl ethers were key monomers in the early polymer Hterature. Eor example, ethyl vinyl ether (EVE) was first polymerized in the presence of iodine in 1878 and the overall polymerization was systematically studied during the 1920s (5). There has been much academic interest in living cationic polymerization of vinyl ethers and in the unusual compatibiUty of poly(MVE) with polystyrene. 

Methyl vinyl ether Ethyl vinyl ether Isopropyl vinyl ether -Butyl vinyl ether Isobutyl vinyl ether... 

Ethyl Vinyl Ether. The addition of ethanol to acetylene gives ethyl vinyl ether [104-92-2] (351—355). The vapor-phase reaction is generally mn at 1.38—2.07 MPa (13.6—20.4 atm) and temperatures of 160—180°C with alkaline catalysts such as potassium hydroxide and potassium ethoxide. High molecular weight polymers of ethyl vinyl ether are used for pressure-sensitive adhesives, viscosity-index improvers, coatings and films lower molecular weight polymers are plasticizers and resin modifiers. 

The high reactivity of pyrroles to electrophiles is similar to that of arylamines and is a reflection of the mesomeric release of electrons from nitrogen to ring carbons. Reactions with electrophilic reagents may result in addition rather than substitution. Thus furan reacts with acetyl nitrate to give a 2,5-adduct (33) and in a similar fashion an adduct (34) is obtained from the reaction of ethyl vinyl ether with hydrogen bromide. 

Ethyl vinyl ether, pyridinium tosylate (PPTS), CH2CI2, it, 0.5 h. ... 

Ethyl vinyl ether [109-92-2] M 72.1, b 35.5 , d 0.755. Contains polymerization inhibitors (usually amines, e.g. triethanolamine) which can be removed by fractional distn. Redistd from sodium. LACHRYMATORY. 

Simple alkyl radicals such as methyl are considered to be nonnucleophilic. Methyl radicals are somewhat more reactive toward alkenes bearing electron-withdrawing substituents than towards those with electron-releasing substituents. However, much of this effect can be attributed to the stabilizing effect that these substiments have on the product radical. There is a strong correlation of reaction rate with the overall exothermicity of the reaction. Hydroxymethyl and 2-hydroxy-2-propyl radicals show nucleophilic character. The hydroxymethyl radical shows a slightly enhanced reactivity toward acrylonitrile and acrolein, but a sharply decreased reactivity toward ethyl vinyl ether. Table 12.9 gives some of the reactivity data. 

The reaction between perfluoraarylmagnesium halides and esters of dicar-boxyltc acids gives, besides the expected keto esters, secondary alcohols as reduction products [29, 30, 31] (equation 10) Such a reduction is enhanced by higher temperature The hydrogen necessary for reduction comes from the solvent, diethyl ether, which is dehydrogenated to ethyl vinyl ether, which has been identified as a by-product in a similar reaction of perfluoroalkyllithium compound [52]... 

The ethoxyethyl ether is prepared by acid catalysis from a phenol and ethyl vinyl ether and is cleaved by acid-catalyzed methanolysis. ... 

Cycloadditioiis in which 1,2-dithietes acted formally as dienes are among the most typieal reaetions of 1,2-dithietes. Tire dithiete 144 is highly reaetive and eapable of reaetions even with simple alkenes and alkynes (60JA1515 61JA3434,61JA3438).Tlius, 144 reaeted with aeetylene to form 191 and 192 with the initial formation of 193, and with tetramethylethylene to give 194. Other [4 + 2] eyeloadditions of 144 involved those with ethylene, cyelohexene, fra s-stilbene, ethyl vinyl ether, butyl vinyl sulfide, 3-hexyne, and DMAD. 

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