Oxolane

In each case the ring is numbered starting at the oxygen The lUPAC rules also permit oxirane (without substituents) to be called ethylene oxide Tetrahydrofuran and tetrahy dropyran are acceptable synonyms for oxolane and oxane respectively... 

Most frequent are oxidations of alkenes that can be converted to a series of compounds such as epoxides, halohydnns and their esters, ozonides (1,2,4 tri-oxolanes), a-hydroxyketones, a-hydroxyketone fluorosulfonates, ot-diketones, and carboxylic acids and their denvatives... 

Chemical Name 1 -Acetyl-4-[4-[[2-(2,4-dichlorophenyl)-2(1 H-imidazol-1 -ylmethyl)-1,3-di-oxolan-4-yl 1 methoxy] phenyl ] piperazine... 

B) A mixture of 2.4 parts of 1 acetyl-4-(4-hydroxyphenyl)piperazine, 0.4 part of sodium hydride dispersion 78% 75 parts of dimethylsulfoxide and 22.5 parts of benzene is stirred for one hour at 40°C. Then there are added 4.2 parts of cis-2-(2,4-dichlorophenyl)-2-(1 H-imidazol-1 -ylmethyl)-1,3-dioxolan-4-ylmethyl methane sulfonate and stirring is continued overnight at 100°C. The reaction mixture Is cooled and diluted with water. The product is extracted with 1,1 -oxybisethane. The extract is dried, filtered and evaporated. The residue Is crystallized from 4-methyl-2-pentanone. The product is filtered off and dried, yielding 3.2 parts (59%) of cis-1-acetyl-4-[2-(2,4-dichlorophenyl)-2-(1 H-imidazol-1-ylmethyl)-13-di-oxolan-4-ylmethoxy] phenyl] piperazine MP 146°C. 

The cationic ring opening polymerization of oxolane (THF) or of N-substituted aziridines can be initiated by oxocarbenium salts [42]. The methacrylic ester unsaturation is insensitive to cationic sites, and polyoxolanes (poly-THF) macromonomers are obtained in good yields. 

High-valency metal fluoride fluorination of pyridine [82JFC(21)171], quinoline [82JFC(21)413], and 2-methylfurans [91 JFC(51)179] has been reported. With 2-methylfuran a complex mixture of stereoisomers of partially fluorinated oxolans was obtained. These can be dehydrofluorinated to fluorooxolens and no furans have been observed. Conformation and structural group were found to influence the direction and readiness toward dehydrofluorination [91 JFC(52) 165]. 

The system can prevent explosion, fire, and venting with fire under conditions of abuse. These batteries have a unique battery chemistry based on LiAsF6/l,3-di-oxolane/tributylamine electrolyte solutions which provide internal safety mechanism that protect the batteries from short-circuit, overcharge and thermal runaway upon heating to 135 °C. This behavior is due to the fact that the electrolyte solution is stable at low-to-medium temperatures but polymerizes at a temperature over 125 °C... 

It was reported that graphite can also be cycled with reasonable stability in di-oxolane-based electrolytes [81, 82], and in other high-molecular-weight ethers such as 2Me-THF, dimethyl THF, and 1-methoxybutane [83],... 

One of the most important factors affecting Qsei [76, 78, 87] is graphite-anode exfoliation, as a result of intercalation of solvated lithium ions. Factors that are reported to decrease (9lR are increasing the EC content in organic carbonates or di-oxolane solutions [98, 991 addition of C02 [31, 87, 99] or crown ethers [8, 71, 78] and increasing the current density [73] (this also lowers <2SE [14] as a result of decrease in (2s P ) ... 

This polymeric oxocarbenium salt readily initiates the cationic ring opening polymerization of oxolane to produce a polystyrene-polyTHF block copolymer. Molecular weight control is provided, polydispersity is narrow and compositional heterogeneity is small59). 

The simple hexaalkylditins, RsSnSnRs, do not disproportionate on heating, but, in oxolane (tetrahydrofuran) or acetonitrile in the presence of a base such as a Grignard reagent, or in the more strongly basic solvent hexamethylphosphoric triamide (HMPT), disproportionation readily occurs at room temperature, and, in HMPT, addition occurs to such alkynes as phenylacetylene and diphenylbutadiyne. The disproportionation is considered to proceed by nucleophilic attack upon tin (259, 260), e.g.,... 

Similarly, triphenyltin hydride reacts with diethylzinc or diethyl-cadmium in a strongly solvating solvent, such as oxolane (tetrahydro-furan) or 1,2-dimethoxyethane, to give the solvated, metal-metal-bonded products (272). 

The Noyori procedure was applied to a total synthesis of baiyunoside, a sweet principle, using 2,3,4-tri-<9-benzyl-D-xylopyranosyl fluoride (18 see Table 1), and a synthesis of glycotriosyl ceramide. A model experiment for the synthesis, using 18, showed a solvent dependence for the a ratio of the products. In this case, the use of acetonitrile, oxolane, or ether gave the a anomer (1,2-a.v), and the use of toluene or hexane gave the P anomer (1,2-trans), preponderantly. 

It has been found that furans undergo hydrogenolyses under very mild conditions. Such conditions are too mild to hydrogenolyze oxolanes (saturated furans). As concerns regioselectivity, the furan C-O bond rupture takes place in the sterically less hindered position, similar to the reaction in the oxolanes. The oxacycloalkene intermediate of an intramolecular Diels-Alder furan reaction was hydrogenolized over Pd/BaS04.27... 

Of the higher oxacycloalkanes, the four-membered oxetanes are similar to oxiranes whereas the higher rings are different. The Pt, Pd, and Ni catalysts cleave the oxolanes and oxanes in the sterically less hindered position (hydro-genolytic cleavage) (Scheme 4.66), whereas Cu is inactive toward these higher rings. 

The most studied area in this held is the dehydration of oxolanes to butadiene. This type of dehydration is catalyzed by various acidic heterogeneous catalysts. For example, 2,2,5,5-tetramethyloxolane can be dehydrated on Pt/Al203 to 2,5-dimethyl-2,4-hexadiene in good yield (Scheme 5.3).34... 

Oxobutanoic acid, a25 Oxolan-2-one, b617 3-Oxo-iV-phenylbutanamide, a24 2,2 -Oxybis(chloroethane), b 163... 

Polyalcohols do not generally interact noticeably with beryllium, probably on account of the low acidity of the alkyl-OH group. Two exceptions are known where solid compounds have been isolated. The complex anion [bis(meso-oxolane-3,4-diolato)Be]2 has been shown to contain two anionic diolato ligands (258). 

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