1.2- Dithioles hydrocarbons

Dimerized fatty acid thioesters (with a dithiol) in combination with fatty amines are sulfur-containing corrosion inhibitors [888]. The corrosion inhibitor solvent is preferably a hydrocarbon. 

The trithione -methides (3-methylene-1,2-dithioles) are iso-77-electronic with the heptafulvenes,71 and possess a basicity comparable to that of the latter. Some true 3-alkylatSd 1,2-dithiolium salts can be obtained by protonation of compounds 52. This method of preparation is rather narrowly limited, however, by the fact that the simple derivatives of 52 (as in the hydrocarbon series) are evidently very unstable and have not as yet been described. These dithiafulvenes become stable, easily handled compounds only when they contain aryl or typical acceptor residues (R and/or R = CN, C02R) in the 6-position.53, 72 This substitution, however, again as in the hydrocarbon series,73 lowers the basicity to such an extent that the dinitrile (52) (Rj = R2 = H, R = R = CN), for example, is not appreciably protonated even in pure trifluoroacetic acid.52... 

The addition provides only one stereoisomer out of the four possible ones. Sodium Amalgam reduction in buffered methanol removes the binaphthyl residue to afford the hydrocarbon and recovered starting dithiol. 

Reductive cyclocondensation of alkane-1,2-dithiols or alkane-1-thio-l,2-diols with [Re(0)3(Tp )] and PPI13 has been investigated and [Re(0)(Tp )(SCH2CH2S)] has also been structurally characterized. The 1,2-diolato complexes are less thermally stable than the sulfur analogs, stable in hydrocarbon solvents for more than one week at 120°C. DFT calculations have been performed on selected derivatives.208... 

Dithioacetals of reducing sugars are obtained by reaction with a dithiol, such as ethane dithiol, and zinc chloride [37] (reaction 4.38). The acetylated dithioacetal can be desulfurized by cartalytic reduction using Raney nickel to reduce the carbonyl group to a hydrocarbon [38] (reaction 4.38). The 1,1-dithioacetal can be used to reversibly protect the aldehyde group, since it can be readily removed by acid hydrolysis. 

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