Thiete 1,1-dioxides synthesis

Chiral thietane dioxides, synthesis of 449 Chiral thiete dioxides, synthesis of 449 Chlorine compounds, as oxidizing agents... 

Asymmetric induction and the synthesis of optically active thietane and thiete dioxides can be achieved via the basic strategy depicted above (equation 87), by using optically active enamine in the first (2 + 2) cycloaddition187 (equation 90). [Pg.449]

The preparation and investigation of the thietane oxide system (5a) is largely associated with stereochemical and conformational studies . The investigation of the thietane dioxides (5b) is substantially related to the chemistry of sulfenes , the [2 -I- 2] cycloaddition of which with enamines is probably the method of choice for the synthesis of 5b . The study of the thiete dioxide system (6) evolved, at least in part, from the recognition that the unstable thiete system 183 can be uniquely stabilized when the sulfur in the system is transformed into the corresponding sulfone , and that the thiete dioxide system is very useful in cycloadditions and thermolytic reactions. The main interest in the dithietane oxides and dioxides (7) appears to lie in the synthetic challenge associated with their preparation, as well as in their unique structural features and chemical behavior under thermolytic conditions . ... 

Application of the enamine-sulfene cycloaddition allowed the synthesis of 78 and 79 from the corresponding a,/l-unsaturated amines and sulfenes. Similarly, using enamine 80, the crystalline morpholino thietane dioxides (81) were produced. Elimination via the N-oxide gave the corresponding thiete dioxide, whereas reduction by LiAlH4 yielded the thietane 82. 

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... 

Thiabicyclo[3.1.0]hex-3-ene synthesis, 4, 784 9-Thiabicyclo[3.3.1]nonane 9,9-dioxide bond angles, 7, 409 5-Thiabicyclo-2-pentene, 1,2,3,4-tetrakis(trifiuoromethyl)-rearrangement, 7, 153 2H-l,2-Thiaborin dibenzo fused, 1, 658 1-Thia[2.2.2]cyclazines, 4, 479 5-Thia[2.3.3]cyclazines, 4, 481 Thiacyclobutadienes — see lH-1 A -Thietes... 

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). 

H-Benzo[6]thiete synthesis, 4, 824 Benzothietes ring opening, 7, 423 synthesis, 4, 824 Benzothietide anions stability, 7, 419 1H-1 A4-1 -Benzothiins pxidation, 4, 969 stability, 3, 926 structure, 3, 894 Benzothiins, dihydrodisproportionation, 3, 908 lH-2-Benzothiin, 3,4-dihydro-2,2-dioxide... 

The first synthesis of thiete 1,1-dioxide 248 was achieved by elimination of hydrogen chloride from 3-chlorothietane 1,1-dioxide. The overall synthesis from epichlorohydrin (chloromethyloxiran) has been improved in several details. 3-Bromothietane 1,1-dioxide ha.s been obtained by direct bromination of thietane hl-dioxide " and the 3-chloro-derivative has been obtained similarly. " ... 

A different approach was used for the synthesis of the naphtho[ 1,2]thiete 1,1-dioxide 272. The peri-naphthothiete sulfone 20Sb is prepared by photolysis Qf 271612.613 oxidation of the sulfide 205. = ... 

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. ... 

Mustela erminea). An efficient synthesis of thietans (74) has been achieved using P.T.C. and the thietans have been converted to their 1,1-dioxides (75) and then, by bromination and dehydrobromination, to the corresponding thiet 1,1-dioxides (76)... 

The dienophilicity of thiet 1,1-dioxide was utilized to synthesize (73) from tetracyclone, whilst it acted also as a good dipolarophile towards diazoalkanes, giving mixtures of 1-pyrazoline derivatives (74) and (75) in which the isomers (74) predominated, except in the cases of diazomethane and diazoethane, where (75) was the major isomer. Ethyl diazoacetate on the other hand gave the 2-pyrazoline (76). These compounds arc potentially useful for the synthesis of bicyclobutanes by sequential expulsion of nitrogen and sulphur, and thermolysis or photol3rsis of (74 = R =... 

Thiets.—Thiete (111a) and its simple derivatives e.g. 111b) were prepared some years ago they are labile and tend to polymerize. The corresponding 1,1-dioxides 2ire considerably more stable. Stabilization of thiete by annelation with a benzene ring has now been achieved with the synthesis of (114), prepared by the photolysis of (112) the isomer (113) was obtained by acid hydrolysis of (112). ... 

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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