Sulfinic Acids and Related Compounds. 12. Conversions of 1,2-Dithiane 1,1-Dioxide to 4-Mercaptobutanesulfinates and 4,4'-Polythiobis(butanesulfinates)

Article abstract of DOI:10.1021/jo00323a011

1,2-Dithiane 1,1-dioxide (2) was reduced by sodium in liquid ammonia to the disodium salt of 4-mercaptobutanesulfinic acid (4), a member of a new class, which was characterized by conversion to the sulfone-sulfide 5 with 2,4-dinitrochlorobenzene (60percent yield from 2); reduction with NaBH4 led to a polymer.The mercaptosulfinic acid from 4 was an oil, but the monosodium (sulfinate) salt (7) gave a crystalline S-benzylthiouronium mercaptosulfinate (8, 70percent yield) and also could be isolated as such in practicable purity.Sodium polysulfides, Na2Sn, cleaved the dioxide 2 to give 4,4'-polythiobis(butanesulfinates), NaO2S(CH2)4Sm(CH2)4SO2Na (3).When n exceeded 4, sulfur precipitated during the reaction itself, and the product had m = 5.1-5.5.When n was 4, m was 4.9-5.8 (the highest found).When m exceeded 4, however, sulfur slowly precipitated from aqueous solutions of the disulfinates and left the tetrasulfide (m = 4) in solution.The tetrasulfide appears to represent the maximum chain length stable for more than a few hours in water.