Sulfones, sulfoxides, sulfonates

SULFONES, SULFOXIDES, SULFONIC ACIDS AND THEIR DERIVATIVES... 

A mixture of 100 ml of glacial acetic acid, 15 ml of 30% hydrogen peroxide and 5.0 g of allenyl methyl sulfoxide (see Chapter VII-1, Exp. 1) was heated for 30 min at 100°C. The colourless solution was cooled to 20°C and poured into 300 ml of ice-water. The sulfone was isolated by extracting the solution twelve times... 

In sulfoxides and sulfones an adjacent CH group is also deprotonated by strong bases. If one considers the sulfinyl (—SO—) or sulfonyl (—SOj—) groups to be functional groups, then these carbanions are d -synthons. It will be shown later (p. 48f. and 65f.), that these anions may either serve as nonfunctional, d -, d - or d -synthons. 

Sulfones and sulfoxides (145) are obtained usually from the corresponding sulfide by oxidation (Scheme 75) (341). though some of them were prepared from a halothiazole and metal sulfinate (342). 2-Amino-5-acetamidophenylsulfonylthiazole has been prepared by direct heterocycli-zation (343. 344). 

When the desired product is a sulfoxide sodium metaperiodate (NaI04) is an ideal reagent It oxidizes sulfides to sulfoxides m high yield but shows no tendency to oxidize sulfoxides to sulfones... 

Third row elements such as sulfur can expand their va lence shell beyond eight electrons and so sulfur-oxygen bonds in sulfoxides and sulfones are sometimes represented as double bonds... 

Oxidation of a sulfide to a sulfoxide or sulfone is accompanied by a decrease m shield ing of the H—C—S—C proton by about 0 3-0 5 ppm for each oxidation... 

Section 16 16 Oxidation of sulfides yields sulfoxides then sulfones Sodium metaper lodate IS specific for the oxidation of sulfides to sulfoxides and no fur ther Hydrogen peroxide or peroxy acids can yield sulfoxides (1 mole of oxidant per mole of sulfide) or sulfone (2 moles of oxidant per mole of sulfide)... 

Phenyl vinyl sulfoxide is chiral Phenyl vinyl sulfone is achiral... 

Radicofunctional nomenclature finds some use in naming ethers, sulfides, sulfoxides, sulfones, selenium analogs of the preceding three sulfur compounds, and azides. 

Sulfones. Sulfones, R — SO2—R, are named in an analogous manner to sulfoxides, using the word sulfone in place of sulfoxide. In prefixes, the less senior radical is followed by -sulfonyl-. When the > SO2 group is incorporated in a ring, the compound is named as a dioxide. 

Carbamates such as Aldicarb undergo degradation under both aerobic and anaerobic conditions. Indeed the oxidation of the sulfur moiety to the sulfoxide and sulfone is part of the activation of the compound to its most potent form. Subsequent aerobic metaboHsm can completely mineralize the compound, although this process is usually relatively slow so that it is an effective iasecticide, acaricide and nematocide. Anaerobically these compounds are hydrolyzed, and then mineralized by methanogens (61). 

The first aromatic sulfone polymer produced commercially was introduced as Bakelite polysulfone but now is sold by Union Carbide under the trade name Udel. It is made by reaction of the disodium salt of bisphenol A (BPA) with 4,4 -dichIorodiphenyl sulfone in a mixed solvent of chlorobenzene and dimethyl sulfoxide (eq. 12). 

An asymmetric synthesis of estrone begins with an asymmetric Michael addition of lithium enolate (178) to the scalemic sulfoxide (179). Direct treatment of the cmde Michael adduct with y /i7-chloroperbenzoic acid to oxidize the sulfoxide to a sulfone, followed by reductive removal of the bromine affords (180, X = a and PH R = H) in over 90% yield. Similarly to the conversion of (175) to (176), base-catalyzed epimerization of (180) produces an 85% isolated yield of (181, X = /5H R = H). C8 and C14 of (181) have the same relative and absolute stereochemistry as that of the naturally occurring steroids. Methylation of (181) provides (182). A (CH2)2CuLi-induced reductive cleavage of sulfone (182) followed by stereoselective alkylation of the resultant enolate with an allyl bromide yields (183). Ozonolysis of (183) produces (184) (wherein the aldehydric oxygen is by isopropyUdene) in 68% yield. Compound (184) is the optically active form of Ziegler s intermediate (176), and is converted to (+)-estrone in 6.3% overall yield and >95% enantiomeric excess (200). 

Fluorinated and Ghlorfluorinated Sulfonic Acids. The synthesis of chlorinated and fluorinated sulfonic acids has been extensively reviewed (91,92). The Hterature discusses the reaction of dialkyl sulfides and disulfides, sulfoxides and sulfones, alkanesulfonyl haHdes, alkanesulfonic acids and alkanethiols with oxygen, hydrogen chloride, hydrogen fluoride, and oxygen—chloride—hydrogen fluoride mixtures over metal haHde catalysts, such as... 

Sulfoxides are compounds that contain a sulfinyl group covalendy bonded at the sulfur atom to two carbon atoms. They have the general formula RS(0)R, ArS(0)Ar, and ArS(0)R, where Ar and Ar = aryl. Sulfoxides represent an intermediate oxidation level between sulfides and sulfones. The naturally occurring sulfoxides often are accompanied by the corresponding sulfides or sulfones. The only commercially important sulfoxide is the simplest member, dimethyl sulfoxide [67-68-5] (DMSO) or sulfinylbismethane. 

---