An unusual acid-catalysed rearrangement of 8-methylenebicyclo[4.2.0]octan-2-ones; X-ray crystal structure of 4-isopropyl-1,5-dimethylbicyclo[3.2.1]oct-3-ene-6,7-dione
Abstract
The reactions of the 8-methylenebicyclo[4.2.0]octan-2-ones (5) and (6) with toluene-p-sulphonic acid in boiling benzene lead to (9) and (11), respectively, by an unusual rearrangement; the structure of (9) was established by the X-ray diffraction analysis of the derived diketone (10).