Dithiols. Part XXVI. Conversion of aliphatic and alicyclic epoxides into trithiocarbonates
The reactions of meso-2,3-epoxybutane, 1,2-epoxycyclohexane, and 2,3-epoxy-trans-decalin with sodium O-ethyl xanthate, to give the corresponding trithiocarbonates, have been studied under a variety of conditions. Products from the decalin epoxide included 3α-ethoxythiocarbonylthio-trans-decalin-2β-ol, 3α-ethoxythiocarbonylthio-trans-decalin-2β-thiol, 3α-mercapto-trans-decalin-2β-ol, and the meso- and the DL-form of 3α,3α′-thiobis-(trans-decalin-2β-ol). Trithiocarbonates were obtained from all three epoxides by reaction with sodium NN-diethyldithiocarbamate; under mild conditions the intermediate NN-diethylthiocarbamoylthio-compounds were isolated. Cyclisation of trans-2-N-phenylthiocarbamoylthiocyclohexanol by treatment with thionyl chloride or toluene-p-sulphonyl chloride resulted in partial desulphurisation, and gave trans-2-phenyliminoperhydro-1,3-benzoxathiolan; some other approaches to a stereospecific synthesis of a cis-dithiol system are outlined.