C 12 H 12 interconversions: two non-pyrolytic syntheses of tricyclo[5.3.2.0 4,8 ]dodeca-2,5,9,11-tetraene.

Herein, we describe two independent and non-pyrolytic syntheses of an important C12H12 hydrocarbon which had been prepared previously by gas phase thermolysis of compound 6. The first method is based on an unusual dipolar cycloaddition of dichloroketene onto bullvalene. After reductive dechlorination, a Shapiro-Heath reaction of the tosylhydrazone gave the title compound. Alternatively, compound 13 is also obtained from its isomer 6 by a Ag+ catalyzed reaction.