Azapropellanes as phase-transfer catalysts—II: A CMR and PMR study of the three-dimensional structure of 1-azoniapropellanes containing 5- and 6-membered rings

An improved synthesis of 1-azoniatricyclo[4.4.3.0^1,6]tridecane (2) and the preparation of the remaining member of the series, 1-azoniatricyclo[4.3.3.0^1,6]dodecane salts (3) have been achieved. Using a combination of ¹H (at 400 MHz) and ¹³C NMR spectra has allowed the assignment of the signals in the well-resolved ¹H spectra. The results indicate that 1 exists in the all-chair form which undergoes racemization by ring inversion with a rate constant of 0.7 sec^? and further that the counterion in these salts is restricted to associating with only one face of the tetrahedral N atom.