Friedel-Crafts Transannular Alkylation of Benzene with (Z,Z)-1,5-Cyclooctadiene: Reassignment of Two Phenylbicyclooctanes by 13C NMR Spectroscopy and Separate Preparation

Article abstract of DOI:10.1246/bcsj.70.1615

Our previous structure assignment of two phenylbicyclooctanes obtained in Friedel-Crafts transannular alkylation of benzene with (Z,Z)-1,5-cyclooctadiene has been reinvestigated and partly corrected on the basis of ¹³CNMR spectral data, a separate preparation of an authentic sample, and MM3 calculation. The compounds assigned previously to exo-3-phenyl-cis-bicyclo[3.3.0]octane and exo-3-phenylbicyclo[3.2.1]octane among six products should be assigned to 1-phenyl-cis-bicyclo[3.3.0]octane and exo-3-phenyl-cis-bicyclo[3.3.0]octane, respectively, showing that almost all products have bicyclo[3.3.0]octane framework. A new preparative method for an authentic 1-phenyl-cis-bicyclo[3.3.0]octane and MM3 calculations of all products are also presented.