Studies directed toward the synthesis of taxanes: Construction of the tricyclo[5.3.1.0(1,7)]undecane system

The intramolecular nucleophilic substitution of an epoxide by the anion of a nitrile was used to construct the bicyclo[3.1.0]hexane system of 9, deriv ed from 8, and of 14, derived from 13. The intramolecular 1,3-dipolar cyclo addition of nitrile oxide 4, obtained from 14, led to isoxazoline 3. Howeve r, it was not possible to convert 3 into the corresponding beta-hydroxy ket one. Rearrangements of 3 were observed in the presence of dehydrating reage nts leading to compounds 19-21, which are structurally related to 11(15-->1 )abeotaxanes.