Benzenesulfonate esters

Many functional groups are stable under conditions for the alkylation of pseudoephedrine glycinamide enolates, including aryl benzenesulfonate esters (eq 18), rert-butyl carbamate and rerf-butyl carbonate groups (eq 19), tert-butyldimethylsilyl ethers, benzyl ethers, ferf-butyl ethers, methoxymethyl ethers, and alkyl chlorides. The stereochemistry of the alkylation reactions of pseudoephedrine glycinamide and pseudoephedrine sarcosinamide is the same as that observed in alkylations of simple A(-acyl derivatives of pseudoephedrine. 

STRATEGY AND ANSWER Compound A is a benzenesulfonate ester, which forms with retention of configuration from (i )-2-butanol. B is the Sf 2 product formed by reaction with hydroxide, which occurs with inversion of configuration. C is a benzoate ester, formation of which does not affect the configuration at the chirality center. Saponification of C to form D does not affect the chirality center either, since it is an acyl substitution reaction. 

Draw the transition state and final product when the benzenesulfonate ester of 4-phenyl-2S-butanol reacts with KI in THF. 

Malonate anions are convenient sources of ester enolates. They react with halides and a variety of other electrophiles. Acid hydrolysis of the ester followed by decarboxylation gives the mono-acid. An example of this approach used phthalic anhydride 1.178) as a starting material in a reaction with 2-aminoethanol to give 1.179. Conversion of the alcohol moiety in 1.179 to its 0-benzenesulfonate ester... 

Taylor, G. E., Gosling, M. and Pearce, A. Low level determination of p-toluenesulfonate and benzenesulfonate esters in drug substance by high performance liquid chromatography/mass spectrometry./. Chrom. A 1119 231-237, 2006. 

Biphenyl-2,2 -diamine and ring-substituted biphenyl-2,2 -diamines are transformed into dibenzo[rf,/][l JJdiazepines 1 in various ways by reaction with ortho esters (Method A),169 with hydrochlorides of imido acid esters (Method B)170 or with the benzenesulfonates of pro-tonated nitriles (Method C).171 Selected examples are given. 

A detergent, imparting better flexibility to cotton cloth is produced by adding 1% sodium a-sulfo hardened tallow fatty acid methyl ester and 9% disodium a-sulfo hardened palm oil fatty acid to a mixture of 5% sodium n-dodecyl-benzenesulfonate, 5% a-C16-olefmsulfonate, 3% dimethyldistearylammonium chloride, 15% zeolite, 10% sodium silicate, 10% sodium carbonate, 2% soap, 35% Na2S04-7H20, and 5% water [84],... 

Oae found that for both base- and acid-catalyzed hydrolysis of phenyl benzenesul-fonate, there was no incorporation of 0 from solvent into the sulfonate ester after partial hydrolysis. This was interpreted as ruling out a stepwise mechanism, but in fact it could be stepwise with slow pseudorotation. In fact this nonexchange can be explained by Westheimer s rules for pseudorotation, assuming the same rules apply to pentacoordinate sulfur. For the acid-catalyzed reaction, the likely intermediate would be 8 for which pseudorotation would be disfavored because it would put a carbon at an apical position. Further protonation to the cationic intermediate is unlikely even in lOM HCl (the medium for Oae s experiments) because of the high acidity of this species a Branch and Calvin calculation (See Appendix), supplemented by allowance for the effect of the phenyl groups (taken as the difference in between sulfuric acid and benzenesulfonic acid ), leads to a pA, of -7 for the first pisTa of this cation about -2 for the second p/sTa. and about 3 for the third Thus, protonation by aqueous HCl to give the neutral intermediate is likely but further protonation to give cation 9 would be very unlikely. 

R)-(-)-Methyl 3-hydroxybutanoate Butyric acid, 3-hydroxy-, methyl ester, D-(-)- (8) Butanoic acid, 3-hydroxy-, methyl ester, (R)- (9) (3976-69-0) p-Toluenesulfonic acid monohydrate (8) Benzenesulfonic acid, 4-methyl-, monohydrate (9) (6192-52-5)... 

Benzenesulfonic anhydride, 46, 88 Benzocyclobutenes, 1-substituted, from addition of a side-chain carban-ion to an aryne bond, 48, 55 Benzofuran, 46,28 Benzoic acid, 2-phenylethyl ester,... 

Esters of sulfonic acids can rearrange photochemically to give sulfones in moderate yields [147], Thus, phenyl benzenesulfonate (182) cleaves photochemically producing 15% of ort/to-hydroxyphenyl phenyl sulfone (183) and 31.1% of para-hydroxyphenyl phenyl sulfone (184). Besides, 17.4% of phenol (13) is formed... 

Cleavage of the sulfonyl esters to the parent alcohols is accomplished in yields of 60-100% by treatment of the p-toluenesulfonates with 2-6 equivalents of sodium naphthalene in tetrahydrofuran at room temperature (yields 60-100%). Sodium naphthalene is prepared by stirring sodium with an equivalent amount or a slight excess of naphthalene in tetrahydrofuran for 1 hour at room temperature under an inert gas [701]. Benzenesulfonates and bromo-benzenesulfonates are also cleaved to the parent alcohols while alkyl methanesulfonates are reduced also to hydrocarbons [701]. 

It has been found that triamcinolone [101] and the 21-phosphate esters [102] do not under go the Porter-Silber reaction. It was also shown that an increased sensitivity for this procedure can be obtained using the p-hydrazino-benzenesulfonic acid-phosphoric acid reagent [103],... 

L-Tetrahydrofolic acid is a versatile intermediate for the manufacture of various folates, e.g., L-leucovorin [19], which is used in cancer therapy, or Metafolin , which is used as a vitamin in functional food. To our knowledge optically pure L-tetrahydrofolic acid is still obtained by repeated fractional crystallization from an equimolar mixture of diastereoisomers formed by nondiastereoselective hydrogenation of folic acid. In order to increase the yield of l-tetrahydrofolic acid and to avoid recrystallization steps, we checked the utility of our ligand for the diastereoselective hydrogenation of folic acid dimethyl ester benzenesulfonate (Scheme 1.4.4). 

Scheme 1.4.4 Hydrogenation of folic acid dimethyl ester benzenesulfonate.

Blasting expls were improved by incorporating a wetting agent, such as 2-naphthyloxy-acetlc acid laurylamide, 2-naphthylstearyl-amine, or Na benzenesulfonate. The wetting agent renders the water-sol components more readily wettable by the liq nitrate esters, which are also more effectively dispersed. 

A second component in this mutagenic subfraction was shown to have an empirical formula of C8H10O2S. The compound was tentatively identified as the ethyl ester of benzenesulfonic acid. This structural assignment was made from exact mass analysis and interpretation of the following ions a molecular ion at 170.0400 mass units a characteristic... 

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