Electrophilic Transannular Cyclization of Octadehydrodibenzo[12]annulene Reexamined: Indication of the Formation of Both <i>anti-</i> and <i>syn-</i>Indenofluorenes
revealed the formation of both anti-diiodoindenofluorenedione and its syn isomer through the oxidation of the respective tetraiodoindenofluorenes, indicating the occurrence of two modes of iodine-inducedtransannular cyclization. This was supported by the reaction of 2f with bromine, which gave anti- and syn-hexabromodihydroindenofluorenes through interception of indenofluorene intermediates by bromine