Thietes synthesis

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... 

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... 

An attempted synthesis via a retro Diels-Alder route failed, due to the instability of the thiete sulfones at the temperatures required to remove the anthracene blocking group189 (equation 88). 

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]

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

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. 

Thietes, four-membered precursors for the synthesis of 1,3-dilhianes or 1,3-oxathianes, provide access to the target heterocycles by reacting with either carbon disulfide and Lil <2002IJB1234, 2003S340> or, when the ring system denoted in Scheme 110 is aromatic, with diethyl 2-oxomalonate via a [4-1-2] cycloaddition pathway <1998JHC1505>. 

Flash vacuum pyrolysis has been used in the synthesis of 2ff-naphtho[l,2-f>]thiete 8 <98JHC1505> and benzobisthietes 9 and 10 <98TL9639>, and their Diels-Alder cycloaddition reactions have been studied. 

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). 

This chapter continues this work covering the literature of the last 10 years, that is, from 1996 until 2005. The preparation of this review was based on a literature search through SCOPUS and the Beilstein Database, which revealed 104 important papers published within this period. This chapter is organized in accordance with the general structure of CHEC-III, which includes a division into 12 sections including the same aspects as in CHEC-II(1996). For some aspects of thietane and thiete chemistry, such as their synthesis from six- and seven-membered rings, no new papers were published within the discussed period. 

Almost all papers describing the synthesis of thietes and thietanes give a variety of spectroscopic data for new obtained compounds including H and 13C NMR, infrared (IR), and mass spectrometry (MS) spectra. Papers cited in the sections concerning the synthesis should therefore be consulted for routine spectroscopic information on thietane derivatives. 

The synthesis of the thietanes and thietes presented in Scheme 18 is, contrary to the previous ones, quite satisfactory and efficient with much better yields <2004RJ0753>. 

The photodecarbonylation reaction of thiophenones 118a-c leading to the formation of alkyl-substituted thietes 119a-c in high yields turned out to be a useful method for their synthesis (Table 12) <1997HCA510>. 

Synthesis of a range of fused thietes 82 was achieved by utilizing the reaction of tert-butoxide with the thiophos-phoryl-imidazole derivatives 81 (Table 4) <2003S340>. 

Among the available methods to synthesize fused-ring thietes and bi- or tricyclic thietanes (but not spiro-com-pounds), the most efficient method seems to be the synthesis from acyclic precursors with the same number of carbons. Photocyclization reactions lead to thietes and thietanes in satisfactory to high yields. Mono- and disaccharides bearing fused thietane moieties have been synthesized using this method. 

The first synthesis of 3,4-di -/m-butyl-1,2-di thiete (172) was performed by treatment of 173 with Lawesson s reagent (LR). Direct thionation of the diketone 174 failed to yield 172 [82JCR(S)314],... 

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 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. ... 

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