A highly stereoselective synthesis of (E)-1-substituted-1,3-dienes

(E)-1-substituted-1,3-dienes are obtained with high stereoselectivity by the thermal extrusion of SO₂ from 2-substituted-2,5-dihydrothiophene-1,1-dioxides generated by a retro Diels-Alder reaction. An application to the synthesis of (E)-9,11-dodecadien- 1-yl acetate, a sex pheromone of the red-bollworm moth is described.     

Diels-alder reaction with cyclic sulfones. 9.* Synthesis of 10-oxo-1h-tetrahydrofluo-reno[2,1-b]thiophene dioxides*2

The treatment of 5-aryl-4′,6′-dioxo-2,3,3a,4,5,6-hexahydrospiro-[benzothiophene-4,5′-1,3-dioxane] 1,1-dioxides with boron trifluoride etherate in dichloroethane leads to the formation of products of intramolecular acylation, namely, the corresponding 10-oxo-1H-5,5a,10a,10b-tetrahydrofluoreno-[2,1-b]thiophene dioxides. In all cases, 5-aryl-4-carboxyhexahydrobenzo[b]thiophene 1,1-dioxides were also isolated. The product ratio depends on the structure of the aromatic substituent at C(5) of the spiro- adducts. The structure of 4-carboxy-5-(2-methoxyphenyl)-7-methyl -2,3,3a,4,5,6-hexahydro-benzo[b]thiophene 1,1-dioxide was confirmed by X-ray diffraction structural analysis. ^*For Communication 9 see [1]. ^*2Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1503–1512, October, 2008.     

Diels–Alder Reactions with Cyclic Sulfones: VII. Synthesis of 1-Benzothiophene 1,1-Dioxide Derivatives

5-Arylmethylene-2,2-dimethyl-1,3-dioxane-4,6-diones reacted with 5-isopropenyl-2,3-dihydrothio-phene 1,1-dioxide to give the corresponding ortho-addition products, 5-aryl-2',2',7-trimethyl-3,3a,5,6-tetra-hydro-2H-spiro[1-benzothiophene-4,5'-[1,3]dioxane]-4',6'-dione 1,1-dioxides. Their aminolysis resulted in opening of the 1,3-dioxane ring and formation of 4-carbamoyl-7-methyl-2,3,3a,4,5,6-hexahydro-1-benzo-thiophene-4-carboxylic acid 1,1-dioxide whose structure was determined by X-ray analysis. Reactions of the spiro adducts with amines and hydrazine hydrate afforded the corresponding mono- or dicarboxylic acid monoamides (hydrazide).     

Synthesis and reactivity of a stable precursor of 2-cyano-1,3-butadiene

A new, productive synthesis of 3-cyano-2,5-dihydrothiophene-1,1-dioxide (3) is described. This substituted sulfolene serves as a stable precursor of 2-cyano-1,3-butadiene and can be used in the Diels-Alder reactions without isolation of the unstable diene.The Diels-Alder reactions of 2-cyano-1,3-butadiene appear to proceed in high yield only with electron-deficient dienophiles, but ¹³C NMR shows that in some cases the products are a mixture of regioisomeric cycloadducts.     

Synthesis of 3,4-di(methylene)tetrahydrothiophene-1,1-dioxide and its use in organic synthesis

A convenient reaction scheme has been developed for obtaining 3,4-di(methylene)tetrahydrothiophene-1,2-dioxide from the readily available 3,4-dimethyl-2,4-dihydrothiophene-1,1-dioxide through 3,4-di(bromomethyl)-2,5-dihydrothiophene-1,1-dioxide. A feasibility study has been made of the use of the butadiene fragment of the heterocycle in a Dieb—Alder reaction with maleic acid derivatives, and the corresponding adducts have been obtained.DeceasedTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 173–175, February, 1992.     

Synthesis of 1-aryl-3,4-dimethylenepyrrolidines by the thermal elimination of sulfur dioxide

The reaction of 3,4-bis(bromomethyl)-2,5-dihydrothiophene 1,1-dioxide with arylamines to produce 5-aryl-1,3,4,6-tetrahydrothieno[3,4-c]pyrrole 2,2-dioxides was investigated. It was found that the bicyclic compound was obtained in good yields for arylamines with substituent groups with Hammett σ values of less than 0.40. These bicyclic compounds were thermally decomposed to produce the corresponding 1-aryl-3,4-dimethylenepyrrolidines in good yields. Several accompanying products of both of the above reactions were isolated and characterized.     

A study of the conditions of the formation of the cis and trans isomers of N-substituted 4-aminothiolan-3-ol 1,1-dioxides

A mixture of cis- and trans-4-alkyl(heteryl, aryl)aminothiolan-3-ol 1,1-dioxides and (3-hydroxy-1,1-dioxothiolan-4-ylamino)acetic acids have been obtained by the reaction of 2,3-dihydrothiophene-3-ol 1,1-dioxide with aliphatic, heterocyclic, and aromatic amines and aminoacetic acid. The structures of the compounds isolated has been shown by chemical and spectral methods.Translated from Khimiya Geterotskiklicheskikh Soedinenii, No. 4, pp. 475–478, April, 1980.     

Fotochromic Dihetarylethenes: XIX. Synthesis of 1,2-Dihetarylethenes with 2,5-Dihydrothiophene Bridge from Thieno[3,2-b]pyrroles

Reductive cyclization by McMurry method was performed with diketosulfide obtained by treating with Na₂S of compound prepared by regioselective acylation of methyl 2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate with chloroacetyl chloride. As a result was synthesized a photochromic 1,2-dihetarylethene where the fuzed rings are connected by a 2,5-dihydrothiophene ring. The oxidation of the latter provides 2,5-dihydrothiophene-1,1-dioxide bridge.     

Intramolecular interaction in aryldihydrothiophene 1,1-dioxides

The peculiarities of the intramolecular interaction in unsaturated five-membered cyclic sulfones as a function of their structures were studied on the basis of an analysis of the electronic absorption spectra of single crystals of isomeric -aryldihydrothiophene 1,1-dioxides at 4.2°K, the IR spectra of the molecules at 298°K, and the results of x-ray diffraction analysis of 3-phenyl-4,5-dihydrothiophene 1,1-dioxide. In addition to the inductive effect, conjugation of the SO₂ group with the -electron system of 3-phenyl-4,5-dihydrothiophene 1,1-dioxide, which is manifested most appreciably in the excited electronic state, was observed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1056–1059, August, 1977.     

Pyrazino[2,3-c][1,2,6]thiadiazine 2,2-dioxides. Sulfur dioxide analogs of pteridines

Several pyrazino[2,3-c][1,2,6]thiadiazine 2,2-dioxide derivatives have been synthesized for the first time by condensation of suitable 4,5-diamino-1,2,6-thiadiazine 1,1-dioxides and symmetrical 1,2-dicarbonyl compounds. Structures of these compounds have been characterized by their elementary analyses, ¹H-nmr and uv spectra as well as their pK_a values. The most striking differences between this series and the corresponding pteridines are discussed.     

Synthesis of Thiochroman 1,1-Dioxide Derivatives on the Basis of 2,4,6-Trinitrotoluene

Treatment of 2,4,6-trinitrotoluene with -mercaptocarboxylic acid esters and subsequent oxidation gave 2-(alkoxycarbonyl-R-methylsulfonyl)-4-X-6-nitrotoluenes which were brought into Knoevenagel condensation with aromatic aldehydes (heating in benzene in the presence of secondary amine acetates). As a result of intramolecular cyclization, 2-alkoxycarbonyl-3-aryl-2-R-5-X-7-nitrothiochroman 1,1-dioxides (R = H, Me; X = NO₂, R'SO₂) were obtained. The developed procedure opens the way to hitherto unknown thiochroman 1,1-dioxide derivatives.     

Halo Derivatives of 2,4-Dinitrothiolene 1,1-Dioxides: Synthesis and Structure

Procedures were developed for preparing representatives of a new type of halonitrothiolene 1,1-dioxides: mono- and dihalo derivatives of 2,2,4-tri- and 2,4-dinitro-3-thiolene 1,1-dioxides. An X-ray diffraction study showed that 2,5-dinitro-2,3-dichloro-3-thiolene 1,1-dioxide molecules exist in the crystal as enantiomeric pairs; the five-membered rings have the envelope conformation, with deviation of the sulfur atom from the ring plane; the halogen atom and nitro group at the multiple bond are essentially coplanar with the ring.     

Oxygen-17 nuclear magnetic resonance spectral investigation of 3-alkoxy-trans-3,4-disubstituted-thiolane 1,1-dioxides and related compounds

The ¹⁷O NMR spectra of 3-alkoxythiolane 1,1-dioxides indicate that the sulfonyl oxygens are diastereotopic but their chemical shift differences are essentially independent of the structure of the alkyl group in the alkoxy moiety. Eu(fod)₃ enhances the ¹⁷O chemical shift differences between the diastereotopic sulfonyl oxygens in 3-isopropoxythiolane 1,1-dioxide and shifts both oxygens upfield. α,β-Unsaturation deshields the sulfonyl oxygens in both five- and six-membered rings.     

Investigation of substituted 2- and 3-thiolene 1,1-dioxides by PMR spectroscopy with the aid of a lanthanide shift reagent

The reaction of lanthanide shift reagent Eu(FOD)₃ with 3-phenyl- and 3- and 4-chloro-2-thiolene 1,1-dioxides and with 3-phenyl-3-thiolene 1,1-dioxide was investigated by PMR spectroscopy. The geometrical structure of the adduct of the lanthanide shift reagent with 4-chloro-2-thiolene 1,1-dioxide was found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 314–317, March, 1984.     

Staudinger and retro-Staudinger reactions. The dichloro-β-lactam moiety as a useful handle for the synthesis of 4-aryl-2H-1,3-benzothiazine 1,1-dioxides

The dichloro-β-lactam ring, obtained via Staudinger reaction of 4-aryl-2H-1,3-benzothiazines, proved to be a useful protecting strategy for the synthesis of 4-aryl-2H-1,3-benzothiazine 1,1-dioxides. After oxidation of the 1,1-dichloroazeto[2,1-c][1,3]-benzothiazin-2-ones, the thiazine ring could be recovered selectively and in good yield by treatment with base. Thus, novel 4-aryl-2H-1,3-benzothiazine 1,1-dioxides were obtained efficiently.     

Stereoselective preparation of conjugated dienoates and dienamides. New synthesis of pellitorine and pipercide

(E) and (E,E)-conjugated dienoates and dienamides of high stereoisomeric purities are prepared via thermal SO₂ extrusion from cis-2,5-disubstituted-2,5-dihydrothiofene-1,1-dioxides generated by a retro Diels-Alder reaction. Applications of this method to the syntheses of two insecticidal natural dienamides : pellitorine and pipercide and of methyl tetradeca-2E,4,5-trienoate, an insect sex pheromone, are described.     

Synthesis of 2,5-dihydroimidazo[4,5-<Emphasis Type="Italic">e</Emphasis>][1,2,3]thiadiazine 1,1-dioxides—Derivatives of a novel heterocyclic system

5-Formyl-1H-imidazole-4-sulfonyl chlorides reacted with hydrazine hydrate or alkylhydrazines to give 2,5-dihydroimidazo[4,5-e][1,2,3]thiadiazine 1,1-dioxides.     

The preparation of 2H-1,2,3-benzothiadiazine-1,1-dioxides, 11H-11a-dihydrobenzimidazo[1,2-b] [1,2] benzisothiazole-5,5-dioxides, 6H-dibenzo[c,g] [1,2,5] thiadiazocine-5,5-dioxides and 5H-Dibenzo[c,g] [1,2,6] thiadiazocine-6,6-dioxides

o-Benzoylbenzenesulfonyl chlorides (I) were prepared conveniently from aminobenzophenones by diazotization followed by reaction with sulphur dioxide in the presence of Cu⁺, according to the general method of Meerwein. Reaction of the sulfonyl chlorides with hydrazine led to 4-phenyl-2H-1,2,3-benzothiadiazine-1,1-dioxides (II). The latter compounds could be methylated and acetylated readily in the 2-position. The 2-methyl derivative (III) could be prepared also by reaction of the sulfonyl chloride (Ia) with methylhydrazine. Catalytic hydrogenation of 6-chloro-4-phenyl-2H-1,2,3-benzothiadiazine-1,1-dioxide (IIa) gave the 3,4-dihydro derivative (V). Reaction of the sulfonyl chlorides (I) with o-phenylenediamine followed by cyclodehydration led to 11H-11,11a-dihydrobenzimidazo[1,2-b] [1,2]benzisothiazole-5,5-dioxides (VII). One of the latter compounds (VIIa) in sodium hydroxide solution in the presence of methyl iodide or benzyl chloride was transformed into 6-methyl- and 6-benzyl-5H-dibenzo[c,g] [1,2,6]thiadiazocine-5,5-dioxides (VIII), respectively. 5H-Dibenzo[c,g] [1,2,6] thiadiazocine-6,6-dioxides (XIV) were prepared also by cyclodehydration of 2-amino-2′-benzoylbenzenesulfonanilides (XIII).     

N,N′-Linked 1,2-benzisothiazol-3(2H)-one 1,1-dioxides: synthesis, biological activity, and derived radicals

A number of N,N′-linked benzoannelated isothiazol-3(2H)-one 1,1-dioxides, not available via oxidation of isothiazolium salts, were obtained with good yields by reaction of N-amino heterocycles with 2-chlorosulfonylbenzoyl chloride and evaluated for their inhibitory activity toward human leukocyte elastase (HLE) and acetylcholinesterase (AChE). 2-(Phthalimid-1-yl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide and 2-(2-methyl-4-oxo-3(4H)-quinazolinyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide were found to be inhibitors of HLE and tested as potential precursors of nitrogen-centered radicals using 266 nm laser flash photolysis.     

Activity of transition metal sulfides in hydrogenation of thiolene-1,1-dioxides

The activity and selectivity of sulfides of group VI–VIII metals in the liquid-phase hydrogenation of thiolene-1,1-dioxides were studied at elevated hydrogen pressure. The generation of thiolane-1,1-dioxide is accompanied by the substrate decomposition, which is especially intensive for 3-thiolene-1,1-dioxide hydrogenation. These processes follow absolutely independent routes. The catalytic activity of sulfides in the generation of thiolane-1,1-dioxide decreases in the following row: PdS>Rh₂S₃>Re₂S₇>OsS₂>PtS₂>CoOS>WS₂>RuS₂ >NiOS.