Sulfone anion from

The frequency of the symmetric stretch does not vary with degree of neutralization for hydrated membranes, which was attributed to the shielding of sulfonate anions from the electrostatic field of the Na+ ions. 

Endo-brevecomin 115 and an analogue 116, have been prepared from D-erythronolactone, via the intermediate sulfone 114, obtained by diastereoselective acetalation with 4-(phenylsulfonyl)-2-butanone (Scheme 29)49 The key bicyclic framework forming step involved intramolecular alkylation of the a-sulfone anion from 114. The enantiomers of both 115 and 116 were also prepared, starting from 2,3-0-isopropylidine-L-erythrose through the intermediacy of the enantiomer of 114. 

In cation-like catalytic centers (III), the counteranion is MAO and methyl anion derived from metallocene. Imuta et al. have pointed out that a stable ionic compound like (V) is the key structure for high polymerization activities, and proposed that the sulfonate anion from zirconium sulfonate (IV) forms stable cation-like catalytic centers (V) [Eq. (9)] [33]. This zirconium sulfonate (IV) and MAO shows higher activities compared to the corresponding chloride system ... 

The utility of the creation of a y-lactone enolate through 1,4-addition of a carbanion and its interception by an electrophile has also been demonstrated in other classes of natural products, e.g., in the enantioselective synthesis of 10-oxa-l 1-methyl PGE2 analogues22. This synthesis starts with 1,4-addition of the sulfone-stabilized anion from 27 to ( + )-(S )-4-methyl-2-buteno-lide which has been prepared in three steps from (—)-(S)-l,2-epoxypropane. The intermediate enolate 28 is reacted with the acetylenic iodide to give the trisubstituted diastereomeric mixture of lactones 29, which is eventually converted into the pure compound 30, both reactions occurring with high diastereoselectivity. 

Alkylation of flra-chloroaniline (13-1) with 2,2,2-triiluoroethyl trichloromethyl-sulfonate affords the corresponding trifluroethylated derivative (13-2). Reaction of the anion from that with aziridine proper leads to the formation of the diamine (13-3). Acylation of that compound with ortfio-fluorobenzoyl chloride (13-4) proceeds to... 

In the last family, the sulfonate anion is attached to a neutral alkyl spacer unit [-(CH2) -, where n = 2 to 6] that links to the CD structure by a metabolically stable ether linkage. This group of compounds differs from the first two families in that the anionic charge is spaced away from the carbohydrate backbone by the alkyl group. 

The presence of an NH group is essential, since the Boc-p-amino sulfone derived from Pro could only be coupled with lower yields (-20%). This method is also suitable for the preparation of pseudodipeptides having functionalized side chains such as those of Ser and AsnJ72l The p-oxo sulfone 51, which was obtained by reacting Boc-pAla-OMe with the dilithium anion of methyl phenyl sulfone, cleanly reacted with ethyl bromoacetate to give the p-oxo sulfone 52 (86%). The latter was reduced using LLAIH4, which on reductive elimination produced the over-reduced Boc-Alai)i(CH2—CH2]Gly-OMe isostere (80%). 

The loss of stereospecificity in the addition of bis(sulfone) anions to cyclohexenyl allylic acetates was attributed to a scrambling of the stereochemistry of the starting acetate. The ability of Pd° catalyst to effect this epimerization was confirmed in the absence of added nucleophile. This epimerization was attributed to the ability of the acetate to return to add to the ir-allyl complex via attack at the metal center (equation 177).167 This suggestion was confirmed by treatment of a preformed allylpalladium acetate dimer with CO, which resulted in cis migration of the acetate from Pd to the allyl ligand (equation 178).164... 

Basically, the same sulfonated acid dyes which are used to dye wool are also suitable for polyamide (see Sections 4.10.2-4.10.4). In a weekly acidic dye liquor the sulfonate anion of the dye binds to the ammonium cation, formed from the amino end groups of the fiber. Affinity to the fiber can be increased by introducing addi-... 

Atlox 3470, a product of ICI Ltd. is classed as an anionic/ non-ionic surfactant comprised mainly of dodecyl benzene sulfonate (anionic) and a nonylphenol ethoxylate of polyethylene glycol (non-ionic emulsifyer). Recent evidence strongly suggests that the active agent in the viral enhancement coincident with Reye s syndrome is a polyethylene glycol derived from the polyethylene moiety of the parent emulsifyer when the number of repeating ethoxy units in the polymer approaches 9 or 10 (12). 

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