Ether dialkyl alkene

Thus monomers such as isobutylene, styrene, methyl vinyl ether, and isoprene undergo polymerization by cationic initiators. The effect of alkyl groups in facilitating cationic polymerization is weak, and it is only the 1,1-dialkyl alkenes that undergo cationic polymerization. 

Violent reaetions have oeeuiTed between ozone and many ehemieals, a small seleetion being aeetylene, alkenes, dialkyl zines, benzene/mbber solution, bromine, earbon monoxide and etliylene, diethyl ether, hydrogen bromide, and nitrogen oxide. 

Dialkyl(trimethylsilyl)phosphines undergo 1,4-addition to a,/3-unsaturated ketones and esters to give phosphine-substituted silyl enol ethers and silyl ketene acetals, respectively. A three-component coupling reaction of a silylphosphine, activated alkenes, and aldehydes in the presence of a catalytic amount of GsF affords an aldol product (Scheme 76).290 291... 

An alternative method for dialkyl peroxide synthesis is the nucleophilic addition of an alkyl hydroperoxide to an alkene under acid catalysis reported by Davies and coworkers (Scheme 31, path B) ". A similar reaction is the nucleophilic addition of alkylhy-droperoxides to vinyl ethers under acid catalysis, producing perketals. Perketals can be deprotected under mild conditions (THF/water/acetic acid) and this hydroperoxide protection-deprotection sequence has been used by Dussault and Porter as a means for the resolution of racemic hydroperoxides (see also Section II.A.2) . In this respect more detailed studies were carried out with the perketals 75, which were prepared via reaction of alkyl hydroperoxides with vinyl ethers (Scheme 33). Weissermel and Lederer reported that in the presence of teri-butyl hypochlorite, a-chlorodialkyl peroxides can be formed in yields between 12% and 45% (Scheme 31, path C)". a-Alkoxydialkyl peroxides and diperoxyacetals were prepared by Rieche and coworkers via acid catalyzed reaction of one or two equivalents of alkyl hydroperoxides with acetals, ketals or aldehydes (Scheme 31, path D)" or by methylation of the corresponding a-alkoxy hydroperoxides with diazomethane (yields 11%, 27%)" . The diperoxyacetals 76 were isolated in yields ranging from 39 to 77%. 

Similarly, they derived relationships for alkenes, alkylbenzenes, alkanols, dialkyl ethers, mono-, di-, and trialkyl amines, and alkyl halides. For example, the equation for dialkyl ethers (C4-C8) is... 

Alcohols add directly to alkenes under acid or metal catalysis, or under photoinitiated conditions to give dialkyl ethers. Although these additions provide certain ethers under rather mild conditions, alkoxy-mercuration-demercuration is generally a superior method. 

Stable dialkyl ether poly(hydrogen fluoride) complexes have been shown to be convenient and effective fluorinating agents.553 Various open-chain and cyclic alkenes undergo hydrofluorination with dimethyl ether-5 HF (DMEPHF) atroom temperature to furnish the corresponding fluoro derivatives in high yields (73-94%) with excellent selectivities. The fluorination of secondary and tertiary alcohols exhibit similar features. Bromofluorination of alkenes can also carried out with DMEPHF in combination with /V-bromosuccinimide. The homologous diethyl ether and dipropyl ether complexes are also suitable for fluorinations. 

Addition of dialkyl or cyclic ethers to perhalogenated alkenes occurs readily under y-ray irradiation. For example, addition of hexafluoropropene to tetrahydrofuran. ... 

Reaction of aryl vinyl ethers, however, invariably gives mixtures of diazetidines and oxadiazines. The ratio is mainly dependent on the nature of the substituent on the phenyl group and, in part, on the nature of the alkyl group of the dialkyl diazenedicarboxylate and the solvent substituents which enhance the nucleophilicity of the alkene and the electrophilicity of the diazene, and polar solvents that favor a polar mechanism, result in concurrent formation of the diazetidine as the predominant product and vice versa15, l< Similarly, diazetidines 7 and oxadiazines 8 are formed in comparable yields in the reactions of vinyl sulfides with dimethyl diazenedicarboxylate, the ratio is principally dependent on the nature of the sulfur substituent (aryl, alkyl)17. 

Two-laser two-photon results revealed photoisomerization of the cation E,E-11 to its stereoisomer Z,E-11, which undergoes thermal reversion with a lifetime of 3.5 ps at room temperature. Absolute rate constants for reaction of styrene, 4-methylstyrene, 4-methoxystyrene and /i-methyl-4-methoxystyrene radical cation with a series of alkanes, dienes and enol ethers are measured by Laser flash photolysis [208]. The addition reactions are sensitive to steric and electronic effects on both the radical cation and the alkene or diene. Reactivity of radical cations follows the general trend of 4-H > 4-CH3 > 4-CH3O > 4-CH30-jff-CH3, while the effect of alkyl substitution on the relative reactivity of alkenes toward styrene radical cations may be summarized as 1,2-dialkyl < 2-alkyl < trialkyl < 2,2-dialkyl < tetraalkyl. 

The reduction of dialkyl acetals of aromatic aldehydes or ketones with a titanium(II) reagent gives pinacol ethers or the corresponding alkene in high yield (46-100% equation 116). Acetals derived from aliphatic aldehydes or ketones are reduced to the corresponding ethers. 

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