Departrnents of ChenistrY

This paper describes the preparation of cyclic bis(disulfide) dimers derived from trans-2-butene-1 ,4-dithiol- and cis-1,2-cyclohex ane dithiol and the cyc)-ic tris(disulfide) dimer of 1, 3 , 5-tris (mercaptomethyl ) benzene by hiqh di.l-ution oxidation of the thiols with iodine. The stability toward ring-opening polymerization of these th::ee new cyclic disulfides and of nine previously reporteC cyclic disulfides was tested by heating the disulfide with a catalytic amount of sodiun methanethiolate. Norre of the cyclic bis(disulfides) were stable with respect to polymerization under these conditions. The results of these experiments, together with Iiterature reports concerning the stability of similar disulfides, indicate that few simple alkyl disulfides are thermodynarnical ly stable in cyclic form.