Novel acid-catalysed rearrangement of [4.3.2]- and [5.3.2]-propellanones

The reactions of the [4.3.2]- and [5.3.2]-propellanones (1) and (2) with toluene-p-sulphonic acid in acetic acid or sulphuric acid in aqueous tetrahydrofuran led to the tricyclo[4.3.2.01,5]undecane derivatives (5) or (6) and the tricyclo[5.3.2.0.1,6]dodecane derivative(7) or (8), respectively, by a novel rearrangement.