General protocols for the construction of various ring systems employing cation olefin cyclizations initiated by the readily accessible 1, 3-benzodithiolium ion are described. Several substituted tetralones and tetralins can be rapidly assembled by this methodology as can a variety of substituted bicyclo [3.2. l] octane and tricyclic ring systems. The products of these transformations are amenable to interconversion into a range of functionalized ...