Revision of the Stereochemistry of Batzelladine F. Approaches to the Tricyclic Hydroxyguanidine Moiety of Batzelladines G, H, and I

The polycyclic guanidine alkaloids batzelladines F-I isolated from a Jamaican sponge of the genus Batzella in 1997 are of potential value for the treatment of AIDS because they induce p56lck-CD4 dissociation at micromolar concentrations. Comparison of the spectral data for both the synthetic syn and anti tricyclic left-hand portions of batzelladine F establishes that the natural product has the syn rather than the anti stereochemistry originally assigned. Approaches to the tricyclic hydroxyguanidine moiety of batzelladines G-I are described.