Thiet Derivatives

The crystal structure of tra j -2,5-dibromo-7-thiabicyclo[4,2,0]oct-l(6)-ene 7,7-dioxide indicates that the cyclohexene ring is in a half-chair conformation. Methyl 2if-benzothiet-2-carboxylate (57) has been prepared by photolysis of 3-diazo-2-oxo-2,3-dihydro-benzo[6]thiophen it is thermally stable and does not undergo valence tautomerism.  

Thiets react with cyclopentadienylcobalt dicarbonyl to yield complexes of thioacroleins, which are valence tautomers of thiets. Oxidation of 3-ethyl-4-methylthiet and 3-propyl-4-ethylthiet with hydrogen peroxide in acetic anhydride did not give the S-oxides, but instead 2-ethylbut-2-enal and 2-propyl-pent-2-enal, respectively.  

Stable thiet cations (64) reportedly were isolated by treatment of certain /3-keto-sulphides with phosphorus oxychloride. Addition of sodium hydride 

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 

11 Foor-membered Rings ctmtaining One Sulphur Atom and One or More Heteroatoms 

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The complete IR spectrum of thiete has been reported by Dittmer et The most characteristic bands of thiete are the C—H stretching vibration at 3165 cm" and the C=C stretching mode at 1543 cm" Thiete derivatives often show the latter absorption band at 1620 cm " A collection of IR data on the thiazetidines has been assembled. ... 

A general synthetic approach to the thietes is provided by a Hoffmann elimination from aminothietanes 148 (Eq. 24). Other thiete derivatives... 

Electrophilic attack on a metal alkynyl by carbon disulfide. Thiete derivative is used as an intermediate. ... 

Table 1 Bond Lengths and Bond Angles for Thietane and Thiete Derivatives... 

A number of detailed 1H NMR studies of thietane and thiete derivatives have appeared in which all of the coupling constants have been determined and some of these data are summarized in Table 2. Liquid crystal NMR studies of thietane (75MI51400) and thietane... 

Detailed proton NMR spectroscopic data on a variety of fused and spiro thietane and thiete derivatives was tabulated in the corresponding sections of CHEC(1984) and CHEC-II(1996). Therefore, only limited, newer information is presented here. A series of iV-(4-methoxyphenyl), iV-(l -naphthyl), iV-benzyl, and iV-(4-nitrophenyl)-,/V-(thietan-3-yl)benzene- or methanesulfonamides 13 as well as the analogous iV-aryl-iV-(thietan-3-yl)-2-nitroben-zenesulfonamides 14, 3-arylaminothietanes 15, iV-(4-aryl)-iV-(l-oxothietan-3-yl)-2-nitrobenzenesulfonamides 16, iV-(l,l-dioxothietan-3-yl)-Ar-(aryl)-2-nitrobenzenesulfonamides 17, 3-(4-arylamino)thietane 1,1-dioxides 18, and iV-(4-aryl)-iV-(thietan-2-yl)benzamides 19 were identified on the basis of their H NMR spectra <2005RJ01023>. 

XH NMR spectral data for representative thietane and thiete derivatives have been tabulated . In general the -protons of thietanes are deshielded relative to analogous protons in larger rings, e.g., thietane ( = 3.21) and tetrahydrothiophene ( = 2.82). 

An attempted synthesis of thiete by thermolysis (300°) of a Diels-Alder adduct with anthracene was unsuccessful, no doubt because of the thermal instability of thiete.Thiete derivative 215 was obtained by other methods, and structure 217 was suggested as an intermediate in the desulfurization of 216. The unusual dithiolactone 218b is formally derived from a cycloaddition of carbon disulfide with acetylene 218a. " A 2-substituted-3,4-diphenyl-2H-thiete is obtained by treatment of the ylide, 8-methyl-1,3-diphenyldibenzo [e, h]-8-thiazulene, with diphenylcyclo-propenethione. 2-Methoxy-3,4-diphenyl-2H-thiete is one of several products obtained on photolysis of diphenylcyclopropenethione in methanol. ... 

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... 

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