Thiophane, from thiophene

Figure 5 presents the formation of butane obtained on dispersed palladium catalysts from the adsorption of several sulfur compounds thiophene, thiophane, dibutylsulfide, butanethiol, dibutyldisulfide. Twogroups can be observed (1) thiols and disulfides that undergo a rather low-level dissociation in butane and (2) thiophene, thiophane, and dibutylsulfide, which are dissociated to a much larger extent. The dissociation of dibutylsulfide produces a quantity of butane twice that produced from thiophene and thiophane, indicating that the two bonds (sulfur — butyl radical) are broken altogether. 

Sulfur compounds isolated from the lighter petroleum fractions include mercaptans (Z SH), dialkyl sulfides and disulfides (RSR, RSSR), and cyclic sulfides such as thiophanes and thiophenes. 

Heterocyclic systems can also be reduced by this procedure. 2-benzoyl-thiophene and 3-methyl-thiophene undergo reduction to 2-benzyl-(72< )- and 3-methyl-thiophane (129), respectively86. Analogously, 1-methyl-cyclohexane (132) can be obtained from 1-methyl-1-cyclohexene88. ... 

Work carried out at the University of Birmingham (11), in England, by Dr. Emmott on middle distillates has revealed the presence of large amounts of sulfides in virgin stocks. As one ascends the boiling range scale the information on the types of sulfur compounds present becomes more limited. Hoog (26) has examined some Middle East gas oil and has deduced from the results of the several experimental techniques employed that essentially no sulfides, di- or polysulfides, or mercaptans were present and that the sulfur compounds of that specific gas oil were preponderantly of the thiophene and thiophane type. 

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