Thietan 1,1-Dioxides

Heats and enthalpies of oxidation of cis- and trans-3-t-butylthietan 1-oxides to the 1,1-dioxides by perlauric acid at 298 K have been determined. The structures of cis-2,4-diphenylthietan l-oxide and the seven-co-ordinate complex of 3,3-dimethylthietan 1-oxide with the shift reagent Eu(dpm)3 have been established by X-ray analysis. The mass spectrum of thietan 1-oxide shows fragmentation to CsHs and 

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B. 3-Chlorothietane 1,1-dioxide. Thietane 1,1-dioxide (14.0 g, 0.132 mol) is placed in a three-necked, 500-mL, round-bottomed flask fitted with a magnetic stirrer, reflux condenser and a chlorine bubbler, caution sinae ahtovine is poisonous, the reaation involving it should be done in a good hood.) Carbon tetrachloride (300 mL) is added to the flask (Note 4) and the suspension is irradiated by a 250-watt sunlamp positioned as close as possible to the reaction flask without touching it (Note 5) while chlorine is bubbled through the solution for 15 min at a moderate rate (Note 6). A copious white precipitate forms and irradiation and addition of chlorine must be stopped at... 

D. 3,3-Diahlarothietane 1,1-dioxide. Thietane 1,1-dioxide (5.0 g, 0.047 mol) Is placed In a 500-mL, three-necked, round-bottomed flask equipped with a reflux condenser, magnetic stirrer, and chlorine gas bubbler. Carbon tetrachloride (350 mL) Is added and the solution Is irradiated with a 250-watt sunlamp (Note 5) while chlorine Is bubbled through the stirred mixture for 1 hr (Note 9). Irradiation and chlorine addition are stopped and the reaction mixture is allowed to cool to room temperature. The product Is collected by filtration as a white solid (4.0-4.4 g, 49-53%), mp 156-158°C (Note 10). The product can be used without further purification or It can be recrystallized from chloroform. 

Selective chlorination of the 3-position of thietane 1,1-dioxide may be a consequence of hydrogen atom abstraction by a chlorine atom. Such reactions of chlorine atoms are believed to be influenced by polar effects, preferential hydrogen abstraction occurring remotely from an electron withdrawing group. The free radical chain reaction may be propagated by attack of the 3-thietanyl 1,1-dioxide radical on molecular chlorine. 

The following compounds have been obtained from thiete 1,1-dioxide Substituted cycloheptatrienes, benzyl o-toluenethiosulfinate, pyrazoles, - naphthothiete 1,1-dioxides, and 3-subst1tuted thietane 1,1-dioxides.It is a dienophile in Diels-Alder reactions and undergoes cycloadditions with enamines, dienamines, and ynamines. Thiete 1,1-dioxide is a source of the novel intermediate, vinylsulfene (CH2=CHCH=SQ2). which undergoes cyclo-additions to strained olefinic double bonds, reacts with phenol to give allyl sulfonate derivatives or cyclizes unimolecularly to give an unsaturated sultene. - Platinum and iron complexes of thiete 1,1-dioxide have been reported. 

TABLE 5. Selected molecular parameters (A, deg) of 3-bromo-26-thietane 1,1-dioxide in the gas phase37 and in the crystal56... 

The molecular geometry of 3-bromo-A6-thietane 1,1-dioxide, C3H5Br02S,... 

A few studies have been carried out on the parent four- and five-membered cyclic sulfones—for thietane 1,1-dioxide (30) by Scala and Colon65 and for thiolane 1,1-dioxide (sulfolane) (31) by Honda and coworkers66 and, later, by Schuchmann and von Sonntag67. In the former compound, the major photochemical process, in the vacuum UV range, is the initial production of a trimethylene (C3H6) biradical and S02 (equation 9). In both the solid- (77 K) and gas-phase photolyses, formation of a triplet biradical appears to be favored. As well as the expected cyclopropane and propylene, ethylene is also obtained during these photolyses, presumably by a cycloreversion process (equation 10). 

The first thietane 1,1-dioxide to be analy2Ed by three-dimensional X-ray diffraction was trans-4-chloro-3-morpholino-2,2,4-trimethylthietane 1,1-dioxide (33), which has a monoclinic crystal structure with four molecules occupying a unit cell. 

Thietane 1,1-dioxide derivatives reportedly produce sulfur dioxide as well as a variety of other fragments. Peaks resulting from retro cycloaddition fragmentation such as CH2S and CH2S02 are never lacking. 

The reaction of Af,Af-dimethyl-( )-styrylamine (73) with a halogen-substituted methanesulfonyl chloride allowed the first stereoselective formation of the halogenated thietane 1,1-dioxide 74, which then could be converted to the corresponding thiete sulfone 75 via a Cope elimination of the corresponding AT-oxide. ... 

Cycloaddition of sulfenes to a,)8-unsaturated sulfides that contain electron-donor substituents, such as alkyl and arylthio groups, has proved to be a valuable synthetic pathway for the production of thietane 1,1-dioxides. Methylsulfonylsulfene (84) is more reactive than the regular sulfenes because of the activating effect by the strong electron-acceptor properties of the sulfonyl group. If, in addition, a strong electron-donor group, such as the alkylamino function, is provided by the unsaturated sulfide molecule, the cycloaddition proceeds much more readily. 

Paquette has used the chloroketal derivatives of thietane 1,1-dioxide as an especially well-suited model for the theoretical study of the thermally induced intramolecular six-electron ring contraction rearrangement, which is pointed out in Eq. (54) for the ketals of 2-bromocyclobutanone that give cyclopropylcarboxylates. Desulfurization of thietanes to cyclopropane did not prove too successful. ... 

The treatment of cyclopentadienyI-metal-2-alkenyl carbonyl complexes, such as 274 and 275, with SO2 leads to the formation of thietane 1,1-dioxide as ligand (Eqs. 73 and 74). Thietane and platinum(II) have also been found... 

Lack of stereoselectivity in the formation of thietane 1,1-dioxide derivatives from anancomeric aminocyclohexenes. ... 

A summary of 13C NMR chemical shift data for thietanes, thietes and related compounds is given in Table 3. An analysis of these data reveals that thietane 1,1-dioxides, thiete... 

Thietane 1,1-dioxide decomposes cleanly to cyclopropane and sulfur dioxide at 400 °C with an activation energy of 117.5 kJ mol-1 (75MI51401) at higher temperatures some... 

Free radical bromination of thietane 1,1-dioxide takes place at the 3- rather than the 2-position, giving ultimately 3,3-dibromothietane 1,1-dioxide (80) (76JOC3044). This preference for abstraction of a hydrogen atom /3 to a sulfonyl group reflects the instability of a free radical a to a sulfone function. 

Conversion of thietane 1-oxides and 1,1-dioxides back to thietanes can be accomplished with aqueous sodium bisulfite (limited to thietane 1-oxides (72JOC919)) or more generally with LAH, as illustrated for sulfoxide (189) (79JOC4757) and sulfone (190) <65LA(684)92, 69JA2796). Ring-substituted thietanes are often conveniently prepared by ring functionalization of the thietane 1,1-dioxide followed by LAH reduction, as will be illustrated below. 

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