Structure Of Two Derivatives Of Intermediate Compounds In The Synthesis Of Marine Toxins. R. Mariezcurrena, L. Suescun, A. Mombrú, O. González, Laboratory of Crystallography, School of Chemistry, Montevideo, Uruguay

Toxins with a trans-fused polyether skeleton are biologically important. They cause massive fish deaths and human intoxications (red tides). Both compounds are derivatives of racemic intermediates in the synthesis of trans-fused polyether toxins. They are selective activators of voltage-sensitive sodium channels in nerves, heart and muscle. Their structural complexity and their polyether systems make them most attractive from a synthetic point of view (Alvarez, Candenas, Perez, Ravelo, & Delgado Martin, 1995)

The X-ray crystallographic analysis of compounds (1) and (2) allowed us to determined the relative configuration of the stereogenic centers (C1, C2, C3). Both compounds contains a 12 membered ring. Hydrogens of epoxide carbons are trans with respect to the epoxide plane, double bond C5=C6 is cis, and C9=C10 is trans.

We have determined the structures of the p-brome benzoate ester derivatives of the racemic compounds (1) and (2). The refinements converged with R₁=0.0365 and 0.0597 respectively.

Research supported by CSIC and CONICYT (Uruguay).

(1) (2)