Methyl compounds => sulfonate esters

A colleague of yours who investigates the fate of benzene sulfonates and benzene sulfonate esters in natural waters is interested in the stability of methyl-3,4-dichlorobenzene sulfonate (MDCBS) in aqueous solution. Because he has not read Chapter 13 of Environmental Organic Chemistry he asks you to help him to estimate the hydrolysis half-life of this compound in water at 25 °C and at 5°C. In the literature you find rate constants for the neutral hydrolysis of some substituted methyl benzene sulfonates at... 

The best materials are produced by curing unsaturated polyester during copolymerization with different types of unsaturated monomers and oligomers, such as styrene and its derivatives, methyl methacrylate, vinylacetate, sulfone-type compounds, allyl esters, and oligo(ester acrylates).5... 

Tables II to X give the melting points and, where applicable, the optical rotations of the inositols, inososes, inosamines, and quercitols, and of all of their known O-substituted derivatives. Anhydroinositols, although not substitution products in the strict sense, are included, as are the carbonyl-functional derivatives of the inososes. Halogen- and nitro-substituted cyclitols, and the C-methyl-inositols and their derivatives, are not included most of these compounds are referred to in the text. The derivatives are arranged in the following order salts (inosamines) or functional derivatives (inososes), carboxylic esters, borates, nitrates, sulfonic esters, phosphates, glycosides, acetals (and Schiff bases), ethers (and IV-alkyl derivatives), and anhydrides.

At an early date it was already recognized that the ketone (IX) derived from an oxidation of the C-18 carbinol function of methyl reserpate could be of considerable utility for further transformation of the reserpine pentacyclic ring system, but early attempts at the preparation of the desired compound by conventional oxidation, e.g., by Oppenauer s method, AAchlorosuceinimide, sodium dichromate, or chromic oxide in pyridine, were unsuccessful with both methyl reserpate and methyl 18-epireserpate. The ketone was finally obtained by heating methyl reserpate p-bromobenzene sulfonate with dimethyl sulfoxide in the presence of triethylamine (162), a method successfully used for simpler compounds (163). Subsequently, it was found that this oxidation could also be realized with other benzene sulfonate esters of methyl reserpate and 18-epireserpate. That the stereochemistry of the molecule was unaffected was proved by sodium borohydride reduction of the ketone, which gave equal amounts of methyl reserpate and its 18-epimer. This and other simple reactions of the ketone are sketched in Chart III, and additional observations will be given. 

A number of analogous sulfides (XXXI) were prepared when p-toluene sulfonate esters of methyl reserpate were treated with sodium salts of thiophenols or of methyl mercaptan. It can be assumed that, in this reaction, inversion takes place at position 18 as well. Some of the sulfides thus obtained show some antihypertensive activity when given intravenously to dogs, but they are not active orally. No sedative effects were observed with these compounds. 

In the years since the last review of sulfonic esters of carbohydrates, there have been many developments in physical methods for isolation of organic compounds and for their structural elucidation. Column chromatography on a variety of adsorbents has found wide application in the separation and isolation of esters of carbohydrates. Caution should be exercised in the use of alumina as the adsorbent for primary sulfonates on neutral or basic alumina of activity I, selective hydrolysis of the primary sulfonate group occurred with methyl 3,4 - di - O - methyl - 2,6 - di - O - (methylsulfonyl) - a - D - glucopyranoside, methyl 2,3-di-0-methyl-4,6-di-0-(methylsulfonyl)-/3-D-glucopyrano-side, and methyl 4-0-methyl-2,3,6-tri-0-(methylsulfonyl)-a-D-manno-pyranoside in benzene or ethanol-free chloroform. Analogous results... 

A more satisfactory synthesis of compounds of this type has been achieved by use of sulfonic esters. Thus, methyl 4,6-0-benzylidene-3-O - (methyl sulfonyl) - 2 - S - phenyl - 2 - thio - a - D - altropyranoside gave methyl 4,6-0-benzylidene-3-deoxy-2-S-phenyl-2-thio-a-D-ert/ hro-... 

Completely new polymer architecture for 157 nm lithography has been proposed on the basis of quantum chemical calculation of VUV absorption of a number of model compounds [315]. Time-dependent density functional theory (TD-DFT) calculations suggested that sulfonic acid esters are transparent in the 157 nm region. In fact, poly(vinylsulfonyl fluoride) and poly(methyl vinyl-sulfonate) have been found to show low OD157 of 2.1 and 2.2/pm [316]. Various... 

Some inorganic esters of CDs, such as nitrates, sulfates, phosphates etc. have also been synthesized however, the organic (acetyl, benzoyl, propionyl, methyl and carbamoyl) esters have been more frequently used for practical industrial and analytical purposes [6,8]. Ether derivatives are the most important CD derivatives from a practical point of view. These compounds can be prepared either by direct reaction with an alkylating agent or via an intermediate, such as sulfonate esters... 

When a double bond is added to an acyclic co-methoxy arenesulfonate competition between n and methoxy participation is possible. The acetolysis of cis-5-methoxypent-3-en-l-yl p-bromobenzenesulfonate (42a) is anchimeri-cally assisted and yields compounds (43)-(46) as well as the corresponding methyl sulfonate ester unless lithium perchlorate is present.It was shown that lithium perchlorate also prevented (by eliminating return from solvent separated ion pairs) formation of the allylic toluene-p-sulfonate (47), thus products (45) and (46) must be formed from allylic cation (48). 

The epoxidation of trans-2-buten-1 -ol with terf-butyl hydroperoxide catalyzed by titanium tetraisopropoxide in the presence of (+)-diisopropyl L-tartrate, (+)-DIPT, gave aracemic tran5-2,3-epoxybutanol, [a] -50.0°. Treatment of this epoxide with (CH3)2CNCuLi2 gave some 2-methyl-l,3-butanediol, which was converted to a sulfonate ester selectively at the primary alcohol, and thence to the iodide (l-iodo-2-methyl-3-butanol) with sodium iodide in acetone. The iodo compound was reduced with NaBH to 3-methyl-2-butanol of rotation [a -i- 5.00°. Pure (5)-3-methyl-2-butanol has [a ] =- - 5 -34°. Draw and name the major stereoisomer of the epoxide and give the percent of the enantiomer present with it. What would you expect if the D-tartrate were used instead [71]... 

Methylthiomethyl p-tolyl sulfone 257 was shown to react with various esters in the presence of excess NaH, affording compounds 263 which, upon reduction with NaBH4 and further treatment with alkali, can be converted to the corresponding aldehydes344. Oxidation of 263 with hydrogen peroxide gives S-methyl a-ketocarbothioates 264335. 

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