Rearrangement of bicyclo[3.2.0]heptyl precursors to the 7-norbornyl cation in the cryogenic SbF5 matrix

The first direct observation by IR spectroscopy in the cryogenic SbF5 matrix was made of the rearrangement of 2- and 3-chlorobicyclo[3.2.0]heptanes (3) and (4), respectively, to the 7-norbornyl cation 1 and its subsequent transformation into the 2-norbornyl cation 5.