ORGANIC DISULFIDES AND RELATED SUBSTANCES .27. REACTIONS AND SYNTHETIC UTILITY OF CYCLIC DISULFIDES DIOXIDES AND TETROXIDES

Hydrolysis, polarographic reduction, and other reactions were studied of the unsubstituted five-, six-, and seven-membered disulfides, the 1,1-dioxides, and the 1,1,2,2-tetroxides. 1,2-Dithiane 1,1,2,2-tetroxide reacted less readily with thiophenol than the 1,1-dioxide but oxidized a thiolate quantitatively to the disulfide by a mild method of possible general use; its reactivity with nucleophiles resembled that of a disulfide, except for greater susceptibility to alkali (all three tetroxides were readily cleaved at pH 8); its pyrolysis gave tetrahydrothiophene dioxide but in low yield. Generalizations are difficult but seem usually to be for easier cleavage of the five-membered systems than of the six-membered ones (with the seven-membered systems variable) and for greater resistance to self-polymerization or to attack of a thiol by the more oxidized forms but for lesser resistance to hydrolysis and electrochemical reduction. The dioxides and tetroxides are quite promising intermediates for synthesis. 1,2-Dithiane 1,1-dioxide underwent “oxodisulfide cleavage” by thiolate ion to give disulfides 1, 2, and 3 containing a sulfinate moiety, which in turn were converted into alkyl sulfones (4 and 5), an aryl sulfone (6), or a sulfonate (8). A typical disulfide product (4) disproportionated to the symmetrical disulfides comparably with resistant classes, affording a synthesis of a disulfide sulfone. 1,2-Dithiane tetroxide underwent “oxodisulfide cleavage” with alkali to give a sulfonate salt containing a sulfinate moiety (11), which was converted into a disulfide dioxide (12). Product 3 was active as an antiradiation drug. © 1969, American Chemical Society. All rights reserved.