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Vinylsulfone

A key intermediate, 163, which possesses all but one chiral center of (+ )-brefeldin, has been prepared by the enantiocontrolled cycloaddition of the chiral fi,/3-unsaturated ester 162 to 154[107], Synthesis of phyllocladane skeleton 165 has been carried out by the Pd-catalyzed cycloaddition of the unsaturated diester 164 and cobalt-catalyzed cycloaddition of alkynes as key reactions[108]. Intramolecular cycloaddition to the vinylsulfone in 166 proceeds smoothly to give a mixture of the trans and cis isomers in a ratio of 2.4 1[109], Diastereocontrolled cycloaddition of the hindered vinylsulfone 167 affords a single stereoisomeric adduct, 168, which is used for the synthesis of the spirocarbocyclic ring of ginkgolide[l 10],... [Pg.313]

Another type of soHd supetacid is based on perfluorinated resin sulfonic acid such as the acid form of Du Font s Nafion resin, a copolymer of a perfluorinated epoxide and vinylsulfonic acid or soHd, high molecular weight petfluotoalkanesulfonic acids such as petfluotodecanesulfonic acid, CF2(CF2)qS02H. Such sohd catalysts have been found efficient in many alkylations of aromatic hydrocarbons (225) and other Friedel-Crafts reactions (226). [Pg.565]

Manufacture of alkylsulfones, important intermediates for metal-complex dyes and for reactive dyes, also depends on O-alkylation. An arylsulphinic acid in an aqueous alkaline medium is treated with an alkylating agent, eg, alkyl haUde or sulfate, by a procedure similar to that used for phenols. In the special case of P-hydroxyethylsulfones (precursors to vinylsulfone reactive dyes) the alkylating agent is ethylene oxide or ethylene chlorohydrin. [Pg.292]

SG sols were synthesized by hydrolysis of tetraethyloxysilane in the presence of polyelectrolyte and surfactant. Poly (vinylsulfonic acid) (PVSA) or poly (styrenesulfonic acid) (PSSA) were used as cation exchangers, Tween-20 or Triton X-100 were used as non- ionic surfactants. Obtained sol was dropped onto the surface of glass slide and dried over night. Template extraction from the composite film was performed in water- ethanol medium. The ion-exchange properties of the films were studied spectrophotometrically using adsorption of cationic dye Rhodamine 6G or Fe(Phen) and potentiometrically by sorption of protons. [Pg.317]

The alkylation of enamines with nitroolefins, which gives intermediates for reductive cyclization (6S2), also provided an example of a stable cycliza-tion product derived from attack of the intermediate imonium function by the nitro anion (683). A previously claimed tetrasubstituted enamine, which was obtained from addition of a vinylsulfone to morpholinocyclohexene (314), was shown to be the corresponding cyclobutane (684). Perfluoro-olefins also gave alkylation products with enamines (685). Reactions of enamines with diazodicarboxylate (683,686) have been used diagnostically for 6-substituted cyclohexenamines. In a reaction of 2-penten-4-one with a substituted vinylogous amide, stereochemical direction was seen to depend on solvent polarity (687). [Pg.375]

The Dnseoc group was developed as a base-labile protective group for the 5 -hydroxyl in oligonucleotide synthesis. It is cleaved with DBU in aprotic solvents. The condensation of oligonucleotide synthesis can be monitored by UV detection at 350 nm or by fluorescence at 530 nm of the liberated vinylsulfone. ... [Pg.541]

Fig. 10. Plots of the relative rate constants of the hydrolysis of dextrin vs. the mole ratio of vinylalcohol unit to vinylsulfonic acid unit, o PVS VA, Polyvinylalcohol + HPVS (Ref. Fig. 10. Plots of the relative rate constants of the hydrolysis of dextrin vs. the mole ratio of vinylalcohol unit to vinylsulfonic acid unit, o PVS VA, Polyvinylalcohol + HPVS (Ref.
Liebscher and Eppert [100] reported a method for the determination of disulfonates in AOS by titration with Hyamine 1622 in water-trichloromethane-containing phenolphthalein indicator to give vinylsulfonate and total sulfonate concentrations, which are used to calculate disulfonate concentrations. One determination requires 30 min. [Pg.432]

N-Vinylpyridine N-Vinylpyrrolidone Vinylsulfonic acid Figure 12-1. N-Vinylpyridine, N-vinylpyrrolidone, vinylsulfonic acid. [Pg.172]

D. T. Muller. Performance characteristics of vinylsulfonate-based cement fluid-loss additives. In Proceedings Volume, pages 609-617. SPE Rocky Mountain Reg Mtg (Casper, WY, 5/18-5/21), 1992. [Pg.436]

Scheme 8.2 Reaction of vinylsulfone dyes with cellulosic fibres... Scheme 8.2 Reaction of vinylsulfone dyes with cellulosic fibres...
The most commonly employed routes for the preparation of the / -sulfatoethylsulfone group, which is the essential structural feature of vinylsulfone reactive dyes, are illustrated in Scheme 8.5. One method of synthesis involves, initially, the reduction of an aromatic sulfonyl chloride, for example with sodium sulfite, to the corresponding sulfinic acid. Subsequent condensation with either 2-chloroethanol or ethylene oxide gives the / -hydroxyethylsulfone, which is converted into its sulfate ester by treatment with concentrated sulfuric acid at 20 30 °C. An alternative route involves treatment of an aromatic thiol with 2-chloroethanol or ethylene oxide to give the /Miydroxyethylsulfonyl compound which may then be converted by oxidation into the /Miydroxyethylsulfone. [Pg.147]

Malacria has reported the use of epoxysilanes for intermolecular addition reactions to acrylates, acrylonitrile and vinylsulfones [56]. [Pg.42]

Certain mixtures of polymers have been shown to form complexes which exhibit substantially higher than expected solution viscosity under low shear conditions. Xanthan gum blends with guar gum (38, 39), sodium poly(styrene sulfonate) (40), polyacrylamide (41), sulfonated guar gum (38), sodium poly(vinylsulfonate) (40), hydrolyzed sodium poly(styrene sulfonate-co-maleic anhydride) (38), and poly(ethylene oxide) (41) and blends of xanthan gum and locust bean gum have exhibited substantially higher than expected solution viscosity (42, 43). [Pg.15]

Scale inhibitors may also be used in acidizing. These include alcohol ethoxysulfonic acids (152). Scale inhibitors are also used in water and enhanced oil recovery injection wells and include low molecular weight poly(vinylsulfonate), poly(methylmethacrylate-co-ethylenediamine) (153), bis(phosphonomethylene)aminomethylene carboxylic acid, and poly(acrylic acid-co-3-acrylamido-3-methylbu-tanoic acid). Ethylenediaminetetraacetic acid and similar complex-ing agents have been used to remove scale from formation surfaces near wellbores. [Pg.24]

Zhang, Y., Hsieh, Y., Izumi, T., Lin, E. T., Benet, L. Z., EfFects of ketoconazole on the intestinal metabolism, transport and oral bioavailability of K02, a novel vinylsulfone peptidomimetic cysteine protease inhibitor and a P450 3A, P-glycoprotein dual substrate, in male Sprague-Dawley rats, J. Pharmacol. [Pg.188]

Chloroethyl Methyl 1-Chloroacetamide 2-Chloroethyl Vinylsulfide 2-Chloroethyl Vinylsulfone 2-Chloroethyl Vinylsulfoxide 2-Chloroethylchloromethyl Sulfide [(2-Chloroethyl)sulfonyl]ethene 2-Chloroethylthio Ethene 2-(Chloromethyl)-l-propene 2-Chloro-/V-(2-chloroethyl)-N-methylacetamide 2-Ch loro-/V,/V-dimethy lam inoethane 2-Chloro-N,N-dimethylethanamine 2-Chloro-N,N-d imethylethylamine... [Pg.624]

A more recent synthesis of 197 [365] is shown in Fig. 9. Enders introduced the stereogenic centre of (S)-lactic acid into the crucial position 10 in 197. The vinylsulfone B, readily available from lactic acid, was transformed into the planar chiral phenylsulfonyl-substituted (q3-allyl)tetracarbonyliron(+l) tetra-fluoroborate C showing (IR,2S,3 )-configuration. Addition of allyltrimethyl silane yielded the vinyl sulfone D which was hydrogenated to E. Alkylation with the dioxolane-derivative of l-bromoheptan-6-one (readily available from 6-bro-mohexanoic acid) afforded F. Finally, reductive removal of the sulfonyl group and deprotection of the carbonyl group furnished 197. A similar approach was used for the synthesis of 198 [366]. [Pg.150]


See other pages where Vinylsulfone is mentioned: [Pg.453]    [Pg.631]    [Pg.447]    [Pg.460]    [Pg.275]    [Pg.278]    [Pg.94]    [Pg.107]    [Pg.319]    [Pg.142]    [Pg.145]    [Pg.147]    [Pg.22]    [Pg.426]    [Pg.188]    [Pg.188]    [Pg.188]    [Pg.188]    [Pg.144]    [Pg.147]    [Pg.148]    [Pg.183]    [Pg.270]    [Pg.78]    [Pg.149]    [Pg.479]    [Pg.223]    [Pg.238]   


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Butyl vinylsulfonate

Phenyl vinylsulfonate

Vinylsulfonates

Vinylsulfone acceptors

Vinylsulfone dyes

Vinylsulfones

Vinylsulfones

Vinylsulfones Michael reactions

Vinylsulfones aldehydes

Vinylsulfones, addition

Vinylsulfonic acid

Vinylsulfonic acid and

Vinylsulfonic esters

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