The Synthesis of Natural Product Amphidinol 7 Models

The amphidinols (AMs) are a series of polyhydroxylated polyene compounds isolated from the dinoflagellate genus Amphidinium. The first serial amphidinol 1 (AMl) was isolated and characterized by 13C NMR and 2D NMRin 1991. The typical structure of this family contains two tetrahydropyran rings connected by a hexanetriol linker. The family members differ with respect to the hydrophilic chain and hydrophobic chain connected to this common fragment. Members of the AM series exhibit potent antifungal activity against Aspergillus niger, which is one of the most common species of genus Aspergillus. Among the 11 reported amphidinol compounds, the absolute and relative configurations on all the stereocenters has been assigned for only AM3. Recently, amphidinol 7 (AM7) has been isolated and studied. This compound shows less bioactivity for Aspergillus niger compared to AM3. The relative stereochemistry of this polyol segment of AM7 has not determined at C(2), C(8) and C(lO). In order to assign the relative stereochemistry of the C(8) and C(lO) stereocenters of polyol segment of AM7, four model compounds were prepared, and the Universal NMR Data base was utilized for the assignment