Alkyl sulfonates reactions

Alkylation of arenesulfinate salts is a very general reaction for the preparation of alkyl sulfones. Reaction conditions utilizing alcoholic or dipolar aprotic solvents are t) ical, but phase-transfer conditions have been described. Reaction with reactive halides is generally facile (eq 1) triflates have likewise been displaced with ease by p-toluenesulfinate. ... 

The Julia-Lythgoc olefination operates by addition of alkyl sulfone anions to carbonyl compounds and subsequent reductive deoxysulfonation (P. Kocienski, 1985). In comparison with the Wittig reaction, it has several advantages sulfones are often more readily available than phosphorus ylides, and it was often successful when the Wittig olefination failed. The elimination step yields exclusively or predominantly the more stable trans olefin stereoisomer. 

Alkyl sulfonic acids are prepared by the oxidation of thiols (36,37). This reaction is not quite as simple as would initially appear, because the reaction does not readily go to completion. The use of strong oxidants can result in the complete oxidation of the thiol to carbon dioxide, water, and sulfur dioxide. 

The mechanisms by which sulfonate esters undergo nucleophilic substitution are the sfflne as those of alkyl halides. Inversion of configuration is observed in Sn2 reactions of alkyl sulfonates and predominant inversion accompanied by racernization in SnI processes. 

Thiols, the sulfur analogs of alcohols, are usually prepared by Sjv 2 reaction of an alkyl halide with thiourea. Mild oxidation of a thiol yields a disulfide, and mild reduction of a disulfide gives back the thiol. Sulfides, the sulfur analogs of ethers, are prepared by an Sk2 reaction between a thiolate anion and a primary or secondary alkyl halide. Sulfides are much more nucleophilic than ethers and can be oxidized to sulfoxides and to sulfones. Sulfides can also be alkylated by reaction with a primary alkyl halide to yield sulfonium ions. 

Addition products are exclusively obtained from the addition of a-lithiatcd alkyl sulfones to a,/i-unsaturaled ketones5-6, in contrast, 1,4-adducts were obtained as a mixture of diastereomers from the reaction of these anions with a./l-unsaturated esters. The extent of the diastereoselection, however, was not reported6. 

Alkyl halides react with sulfite ion to form alkyl sulfonates, a reaction known as the Strecker reaction (20). "Organic Syntheses"... 

When conjugate addition is carried out under aprotic conditions with stoichiometric formation of the enolate, the adduct is present as an enolate until the reaction mixture is quenched with a proton source. It is therefore possible to effect a second reaction of the enolate by addition of an alkyl halide or sulfonate to the solution of the adduct enolate, which results in an alkylation. This reaction sequence permits the formation of two new C-C bonds. 

Trifluoromethanesulfonates of alkyl and allylic alcohols can be prepared by reaction with trifluoromethanesulfonic anhydride in halogenated solvents in the presence of pyridine.3 Since the preparation of sulfonate esters does not disturb the C—O bond, problems of rearrangement or racemization do not arise in the ester formation step. However, sensitive sulfonate esters, such as allylic systems, may be subject to reversible ionization reactions, so appropriate precautions must be taken to ensure structural and stereochemical integrity. Tertiary alkyl sulfonates are neither as easily prepared nor as stable as those from primary and secondary alcohols. Under the standard preparative conditions, tertiary alcohols are likely to be converted to the corresponding alkene. 

Alkyl sulfonates are frequently used as substrates for nucleophilic substitution reactions. 

Alkyl sulfonates provide an indirect method for carrying out nucleophilic substitution reactions on alcohols. 

The alkoxide ion reacts with the substrate in an SN2 reaction, with the resulting formation of the ether. The substrate must bear a good leaving group. Typical substrates are alkyl halides, alkyl sulfonates, and dialkyl sulfates, i.e. 

Alkylation of hydroxylamines with secondary alkyl halides and alkyl sulfonates like 10 (equation 7) is one of the most frequently used synthetic approaches, especially to enantiomerically pure hydroxylamines such as 11 (equation 7). The reaction proceeds with inversion of configuration and does not produce appreciable amounts of diaUcyla-tion products. Both hydroxylamine as well as N- and O-alkylhydroxylamines have been successfully used. Alkyl trillates are probably the most useful substrates for these transformations since they can be prepared from a large pool of commercially available enantiomerically pure chiral secondary alcohols. 

The direct reaction of paraffinic petroleum fractions to alkyl sulfonates by the Reed process has been extensively investigated in this country. In this process paraffin-rich stocks are reacted with sulfur dioxide and chlorine (16) and processed to sulfonates as indicated by the equations ... 

Fuerstenau and Wakamatsu (1975) examined alumina as a sorbent for dodecyl sulfonate (DS) ions. Alkyl sulfonates, R-SO3, do not participate in substantial ligand exchange reactions with alumina. 

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