Thietane 1,1-dioxides acidity

Ethylmagnesium bromide Cyclopropanesulfinic acids from thietane dioxides... 

Oxidation of simple thietans with peroxy-acids gives monoxides and dioxides.However, oxidation of tetraphenyl-2-thietanone (89) with m-chloroperoxybenzoic acid gives (90), which is a stable carboxylic-sulphinic acid anhydride. Thietan dioxides are formed in the oxidation of thietans by NaMn04. 2-Arylsulphonyl-3-aryl-oxaziridines oxidize sulphides (including thietans) to sulphoxides. 3-Hydroxythietan can be oxidized to 3-thietanone, without oxidation at sulphur, with DMSO and benzoic anhydride. ... 

Formation.—Preparation of thietan oxides by oxidation of thietans is covered in the previous section. Cycloaddition of sulphenes to electron-rich alkenes, the other important method of preparation of episulphones, has been further used for the preparation of a-chloro- and /S-amino-, cf-sila- and -amino-, and cf-alkoxycarbonyl- and -amino-thietan dioxides. The sulphonyl enamine (96) can be converted into the thietan dioxide (97) by treatment with acid, a procedure that usually hydrolyses enamines to ketones. Regeneration of (96) from (97) occurs on heating in alcoholic base. Thiet sulphone cyclo-adds to cyclopentadiene to give the Diels-Alder adducts with an exo/endo ratio of 0.25. ... 

It is noteworthy that in spite of the demonstrated acidity of the a-hydrogens in thietane oxides and dioxides, attempted mono- or dialkylations of these systems have been unsuccessful thus far. 

The order of decreasing Lewis basicity toward trimethylaluminum is thiane, thiolane, diethyl (or dimethyl) sulfide, thietane and 2-methylthiirane (67IC1461). Thietane can be protonated at -60 °C with fluorosulfonic acid in antimony pentafluoride-liquid sulfur dioxide the NMR spectrum shows bands at 8 7.40 (S—H) and 3.20-4.40 p.p.m. (C—H) (71JOC1121). 

The basicity of thietanes has been discussed in Section II.3.E. The conjugate acid of thietane has been observed by nmr spectroscopy in fluorosulfonic acid-antimony pentafluoride-sulfur dioxide at —60° and in the mass spectrum. Treat-... 

Oxidation of thietane 1-oxides to thietane 1,1-dioxides is easy, but not particularly important except as a structure proof, since most sulfones can be made directly from the sulfides. Oxidation reagents that have been used on the sulfoxides are hydrogen peroxide-acetic acid, hydrogen peroxide-formic acid, perbenzoic acid, peroxydodecanoic acid, " and perlauric acid. The relative rates of oxidation of four-, five, and six-membered sulfoxides with perbenzoic acid in 40% dioxane at 25° were similar. Oxidations were more rapid at high pH. 

A spirothietane sulfone-oxetane is a comonomer in the preparation of polyethers. A polymer obtained from this sulfone in a solution of bis(3,3-chloromethyl) oxetane with phosphorus pentafluoride can be spun to drawable filaments. Thietane sulfone spirocyclic carbonates may be polymerized via the carbonate group to high-molecular-weight solids said to be useful in laminating. Thietane 1,1-dioxide improves the dye receptivity of poly (acrylonitrile), viscose, cellulose acetate, and poly(vinyl chloride). It is also reported to be a stabilizer for nitric acid in oxidizer mixtures for rocket motors. 2-Methylthietane 1,1-dioxide is claimed to be superior to sulfolane (thiolane 1,1-dioxide) in the liquid extraction of aromatic hydrocarbons from mixtures with saturated hydrocarbons. " A number of bis(3,3-alkoxy) thietane 1,1-dioxides have been proposed as intermediates in the preparation of cyanine dyes useful as photographic sensitizers. " ... 

The pKa of thietane 1,1-dioxide in dimethyl sulfoxide at 25° was estimated to be greater than 30. Acyclic sulfones were more acidic. 

In addition to the unsubstituted sulfene itself, the various substituted sulfenes used in the preparation of thietane 1,1-dioxides are listed in Table 4. Although the usual method for generating the sulfenes is by treatment of a methanesulfonyl chloride with triethylamine, sulfenes have been obtained by the reaction of phenyl-methanesulfonyl fluoride with phenyllithium, by treatment of a-chloro-ethanesulfinic acid with refluxing triethylamine,by treatment of 4-nitro-phenyl or 2-chloro-4-nitrophenyl, esters of arylmethanesulfonic acids with potassium t-butoxide or 2,6-dimethylpyridine, respectively, by treatment of diazoalkanes with sulfur dioxide" (e.g., to give 146) and by thermolysis of a Diels-Alder adduct of sulfene." ... 

Treatment of cis- or tra 5-2,4-diphenyl thietane 1,1-dioxide with t-butoxy-magnesium bromide or ethylmagnesium bromide gives sultines (cyclic sulfin-ates) in which the stereochemistry is preserved (e.g., 171) and cyclo-propanesulfinic acids (e.g., 172). Bases such as hydroxide ion or triethyl-amine cause ring-opening of 3-amino substituted thietane sulfones via an elimination reaction as shown for The... 

The thietane ring of the carboxylate derivative 352 is apparently opened by loss of carbon dioxide. possibly via a thiete intermediate. Isonitriles and ynamines effect ring-expansions of 2,4-bis(imino)thietanes, and similar reactions of enamines and ynamines with tris(imino)thietane, 353 have been reported. The nucleophiles — methanol, ethanethiol, and diethylamine — attack the a-carbon atom of 353, which bears the iminosulfonyl group, to give ring-opened products, for example, 353a. The reactions with sodium azide or hydrazoic acid take a different course. ... 

Hydrogen peroxide or peroxy acids oxidize thietanes to 1,1-dioxides (cyclic sulfones) via 1-oxides ... 

Thietane 1,1-dioxide ring from sulfonic acid chlorides O... 

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