C-13-H-1 COUPLING-CONSTANTS IN CARBOCATIONS .8. APPLICATION OF THE DELTA-J EQUATION TO TERTIARY DICYCLOPROPYLCARBINYL CATIONS - THE METHYL DICYCLOPROPYLCARBINYL, (1-ALPHA,3-BETA,5-BETA,7-ALPHA)-2-METHYLTRICYCLO [5.1.0.0(3,5)]OCTAN-2-YL, 7-ALPHA)-2-METHYLTRICYCLO[5.1.0.0(3,5)]OCTAN-2-YL, AND 3-METHYLTETRACYCLO[3.3.1.0(2,8).0(4,6)]NONAN-3-YL (TRIASTERYL) CATIONS

One-bond C-13-H-1 coupling constants have been determined for the titl e cations (10, 15, 20, and 25) in superacids and the values for the ca rbons adjacent (alpha) to the cationic centers compared with those of the appropriate model ketones to obtain the Delta J values. These valu es were found to be in the range 10-15 Hz, approximately one half that expected for a single cyclopropylcarbinyl cation. This has been inter preted in terms of delocalization of charge into the second cyclopropy l group in those cations which can adopt double bisected conformers, 1 0, 20, 25, and in terms of averaging of the coupling constants as a re sult of two different dihedral angles in cation 15. New methods for th e synthesis of precursors to the 2-methyltricyclo[5.1.0.0(3,5)]octan-2 -yl cations, 15 and 20, have been developed.