Abstract The successful application of the nickel catalyzed, intramolecular [4+ 4] cycloaddition of bis-dienes to the preparation of both the AB and BC ring systems of the taxane diterpenes is described. This cycloaddition methodology provides the basis for a general and efficient route to angularly alkyl-substituted bicyclo [6.4. 0] dodecanes and to bicyclo [5.3. 1] undecanes.