2//-Thiopyran, 4-methyl-2,3,6-triphenyl

The same, relatively stable, carbanionic species (24) is produced by the action of bases on 2,4,6-triphenyl-2H- and -4H-thiopyrans methylation and acetylation of the anion lead to 4,4-disubstituted 4H-thiopyrans (25). Products with this substitution pattern (25 R = p-Me2NC6H4) are also obtained, with the similar 2H-thiopyran derivatives, from the supposed thiabenzene (26 R = p-Me2NC6H4). ... 

Di-te/Y-butyl-4//-thiopyran (363) as well as its 4-methyl derivative 243 were readily aromatized to thiopyrylium salts 403 using trityl tetra-fluoroborate.286 2,4,6-Triphenyl-4//-thiopyran (45) (R = Ph) was analogously converted to salts 404 by the action of methyl iodide, dimethyl sulfate, triethyloxonium tetrafluoroborate,39 perchloric acid,362 or oxygen in acetic acid.363... 

Methyl-2,4,6-triphenyl-4//-thiopyran (47) and 2,4-diphenyl-3-methyl-6-fe/7-butyl-4//-thiopyran (58) reacted with perchloric acid in acetic acid or with oxygen to give perchlorates 405a105,362,364 and 405b.98,363 Analogously,... 

Methyl-2,4,6-triphenyl-2f/-thiopyran (2461) reacts with hydrogen peroxide in acetic acid to produce sulfoxide 411,39 whereas condensed 2//-thio-pyrans 412 and 414 gave the corresponding sulfones 413100 and 415,368 respectively. 

The oxidation of the S atom of 4-substituted 2,4,6-triphenyl-47/-thiopyrans with either NaKT/MeOH/AcMe or H2O2/ACOH affords mixtures of the respective cis and trans 477-thiopyran 1-oxides as determined by crystal structures when the 4-substituent is a methyl group <2005NCS165> the boat conformations are rather flattened, but the 4-benzyl compounds have planar thiopyran rings <2005NCS420>. 

Rather surprisingly 2,4,6-triphenyl-4/f-thiopyran (74) is oxidized to the corresponding thiopyrylium 9 by alkylating agents, such as methyl iodide, dimethyl sulfate, and triethyloxonium fluoroborate (62JA2090). 

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