Thiete 1,1-dioxides additions

Base-induced eliminative ring fission, in which both the double bond and the sulfone function take part, has been observed in thiete dioxides . The reaction can be rationalized in terms of initial Michael-type addition to the double bond of the ring vinyl sulfone, followed by a reverse aldol condensation with ring opening. The isolation of the ether 270c in the treatment of 6c with potassium ethoxide (since the transformation 267 268 is not possible in this case) is in agreement with the reaction mechanism outlined in equation 101 . 

The synthesis and properties of optically active thiet 1,1-dioxides have been reviewed. The generation of sulphenes from p-nitrophenyl sulpho-nates is claimed to have advantages in the preparation of 3-amino-4-arylthiet 1,1-dioxides from acetylenic amines, principally in the avcndance of the presence of triethylamine hydrochloride, which is believed to cause isomerization of the thiet derivative. Several other thiet dioxides have been obtained by reaction of a sulphene with an acetylenic amine. - They are claimed to be anti-inflammatory agents. The formaticm of a thiet 1,1-dioxide from acetylenic sulphine (167) and an enamine has been noted previously. A number of substituted thiet dioxides have been prepared by addition of sulphene to enamines followed by a Cope elimination of the amine. These compounds were tested for analgesic activity but none was found. Thiet 1,1-dioxide (123) is obtained from... 

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. 

Chloroth1ete 1,1-dioxide is a potentially useful intermediate for the preparation of other 3-substituted thiete 1,1-dioxides via addition-elimination reactions. 

The susceptibility of the thiete 1,1-dioxides to nucleophilic addition reactions can be utilized to produce 3-substituted thietane derivatives. For example, the thus easily attainable 3-cyano and 3-nitroalkyl-substituted derivatives could be reduced to the 3-aminomethylthietanes ° (Eq. 61). 

Nucleophilic attack by an amino group on the carbonyl function of a /3-thiolactone forms the basis for a novel peptide synthesis, as illustrated by the preparation of (63) (64RCR493). Amines undergo Michael addition to the carbon-carbon double bond of thiete 1,1-dioxide (61) (62JA399). 

Addition of nucleophiles [OEf, CN , (CH3)2NH, CgHnNH, CH3CH N02,H2S] to the double bond of thiete 1,1-dioxides is generally... 

Diels-Alder reactions of thiete 1,1-dioxides occur readily as exemplified by the syntheses of 151 ° and 152. Adducts of thiete 1,1-dioxide with tetraphenylcyclopentadienone or a-pyrone ° are thermally unstable. Thiete 1,1-dioxides also undergo 1,3-dipolar additions with diazoalkanes, (e.g., the formation of 153 from which the strained bicyclic thietane sulfone 154 is obtained) " nitrile oxides, and cycloadditions with the MA -dimethylenamine of isobutyraldehyde (e.g., the formation of 155). ° ... 

H-benzo[b] thiete 1,1-dioxide 269 has been obtained in a 19% overall yield from thietane 1,1-dioxide and thiete sulfone 270. Diels-Alder additions of... 

Additions of the Michael type of nucleophiles to the carbon-carbon double bond of thiete 1,1-dioxides to give 3-substituted thietane 1,1-dioxides occur readily. The addition of hydrogen has been discussed in Section A. Nucleophiles include cyanide, the anion of nitroethane, the lithium salt of r-butyl o-tolyl sulfone, dimethylamine, cyclohexylamine, ethoxide, and hydrogen sulfide. The reaction is exemplified by the synthesis of 278. Additions to 3-chloro-2H-thiete 1,1-dioxide most likely proceed by an addition-elimination mechanism an example is shown for the addition of the anion of dimethylmalonate to give 279. The replacement of a 3-morpholinyl group by a 3-A methyl-A-phenylamino group in thiete 1,1-dioxide is another example of addition-elimination. An addition of ethoxide with elimination of p-nitrophenyl anion may occur with 268 (Ar = / -N02C6H4). " Addition of bromine via N-bromo-succinimide to the double bond of 4-phenyl-2H-thiete 1,1-dioxide occurs only in 1.5% yield. ... 

The addition of hydroxide ion to thiete 1,1-dioxides yields acyclic sul-... 

The cycloaddition of sulfenes with enamines provides a good synthetic route to thiete 1, 1-dioxides (174) (see Chapter 7, p. 115) (Scheme 69).8 Thiete-1, 1-dioxides like (174) react with alkylamines by conjugate addition to yield the corresponding amino derivatives (175), and by heating in the presence of a reactive alkene, e.g. norborene (176), they form the [2+4] cycloadducts, e.g. (177) (Scheme 69). 

Triethylamine Nucleophilic addition Thioethers from ethylene derivatives 3>Subst. thietane 1,1-dioxides from thiete 1,1-dioxides... 

Some improvements in the synthesis of thiet 1,1-dioxide have been reported, and 2-phenylthiet 1,1-dioxide, 2-benzylthiet 1,1-dioxide, and 4-methyl-2-phenyl-thiet 1,1-dioxide have been prepared. The Michael addition of HCN to... 

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