Tandem Rearrangement Involving a β-Hydroxysulfoxide and Cyclization Processes Toward the 1-Benzenesulfonyl-5-benzenethio-1,2,2a,3,4,5-hexahydrobenz[c,d]indole Oxygenated at the 4-Position
Treatment of compound 4 with trifluoroacetic anhydride under reflux in chlorobenzene underwent a tandem rearrangement to produce compound 5. When the acetylated derivative of 4, was treated with trifluoroacetic anhydride in the presence of Lewis acids produced two cis cyclized conformers 7a and 7b, presumably through the intermediate B.