Abstract Under neutral conditions cis sulfoxides 5 underwent a sigmatropic rearrangement with 2-methylene hydrogens to give sulfenic acids 18, followed by Cyclization to dihydro-1, 4- dithiins 2. The trans sulfoxides 6 rearranged involving 2-methyl hydrogens to form isomeric dihydrodithiins 3 via sulfenic acids 19. In the reactions of both the sulfoxides, sulfides 4 and disulfides 11 were also formed as minor side products. In the presence of acid catalyst cis ...
