Dithioles

2-Dithioles.—A number of charge-transfer complexes of 1,2-dithiolium cations, e.g. (264), with tetracyano-p-quinodimethane and tetrathiosquarate salts have been described.3,5-Diphenyl-l,2-dithiolium perchlorate (265) reacts with methyl cyanoacetate to give the thiapyrone (266) cyanoacetamide, on the other hand, yields the pyridone (267). Photochemical arylation of the dithiolethione (268) with aryl bromides leads to the arylthio-dithiolium bromides (269) the thione (268) reacts with 4-phenyl-l,2,4-triazoline-3,5-dione to form the zwitterion (270) with loss of the exocyclic sulphur atom. The 

Bazbouz, J. Coste, H. Cristol, and F. Plenat, Tetrahedron Lett., 1979, 11. 

Rearrangements Involving the Pivotal Carbon Atom in the Starting Ring 

Dithiolopyrrolones are a class of potent antibiotic natural products found in both Gram-negative and Gram-positive bacteria, and are characterized by the unique pyrrolinonodithiole (4//-[l,2]dithio[4,3-fc]pyrrol-5-one) nucleus [376], Aureothricin 

FIVE-MEMBERED HETEROCYCLIC RINGS AND THEIR FUSED DERIVATIVES 

The first total synthesis of dithiolopyrrolones was described by Schmidt et al. as intermediate in the synthesis of thiolutin, aureothricin, and holomycin [388]. 

The holomycin biosynthetic gene cluster in S. clavuligerus has been identified and characterized. It consists of 12 genes, spanning in about 17.6 kb region, and contains 

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C3S2 s s — — — l,2-Dithiolane-4-carboxylic acid 3-phenyl-l,2-dithiolylium iodide 4-methyl-1,2-dithiole-3-thione ... 

In the 1,2-dithiole series such imines are readily isolated they can be alkylated or protonated, e.g. (448) (449) (66AHC(7)39). 

Alkylisothiazolium salts (61) undergo N—S bond cleavage when treated with hydrogen sulfide or thiophenol to form acyclic products (62), but 2-aryl compounds give 1,2-dithioles (63 or 64 Scheme 9) (75SST(3)54l, 77SST(4)339). 

Sodium or potassium hydrogen sulfite reacts with several thiiranes to give disulfides of /3-mercaptosulfonic acid salts (76EGP122086). Potassium thiocyanate in dimethylformamide or aqueous ethanol isomerizes thiiranes (Scheme 84) (72CJC3930). 1,2-Dithiols are obtained by treatment of thiiranes with NaBH2S3 obtained from sodium borohydride and sulfur (73TL1401). 

Dithiole-3-sulfonyl hydrazides alkali metal salts,... 

Dithiole-3-thione, 5-amino-mass spectra, 6, 787 synthesis, 6, 804, 806... 

Dithiole-3-thiones alkylation, 6, 801, 810 C(ls) binding energy, 6, 788 dipole moments, 6, 788 fused... 

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