[5.3. 1] Propellanes eg, the tricyclo [5.3. 1.01, 7] undeca-2, 4-dien-10-one 8 and the corresponding methylidene compound 10 were prepared from methyl cinnamate 2 in several steps involving rhodium (II) acetate mediated cyclization of 4 to 6 as a key step. The selective central cyclopropyl bond cleavage in 8 and 10 by lead tetraacetate provides the basis of a new approach to the construction of carbocyclic frame of A, B ring of Taxol.
