Thioethers from dithioacetals

Dithioacetic acid Reductions of sulfur compds. with dithioacetic acid Thioethers from sulfoxides... 

If the substrate is an alcohol, some dialkyl ethers can be synthesized in a two-phase version of the Williamson synthesis, and thioethers or dithioacetals result from alkylation of thiols, with alkyl halides or CH2CI2 respectively, under similar conditions. The related reaction of equation (2) has been used to make an evaluation of several catalysts, and it has been found that the larger, more symmetrical, quaternary ions are the most efficient. 

Hg(OAc)2, H2O, 80% AcOH, HSCH2CH2SH, 25°, 5-20 min H2S, 2 h, high yield. The removal of an 5-benzylthiomethyl protective group from a dithioacetal with mercuiy(II) acetate avoids certain side reactions that occur when an 5-benzyl thioether is cleaved with sodium/ammonia. The dithioacetal is stable to hydrogen bromide/acetic acid used to cleave benzyl carbamates. 

Reactions have been carried out between aldehydes or ketones and esters of trithiophos-phorous acid (equation 35 R = R S) or those of phosphonodithious acids (R = Et), from which the products are esters with thioether substituents . Benzaldehyde dithioacetals, PhCH(SR)2 (R - El or Pr ), and the sulphide, P4S2 interact in an entirely novel manner to give products which include the perthio-phosphonic and -phosphinic esters 172 and 173 . ... 

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