Cytotoxic hydroxypolygodials. X-Ray molecular structure of (1R,3S,5aS,-9aS,9bR)-1,3,5,5a,6,7,8,9,9a,9b-decahydro-1,3-dimethoxy-6,6,9a-trimethylnaphtho[1,2-c]furan

Hydroxypolygodials, designed to have the simplified structure of the cytotoxic sesterterpene deacetylscalaradial isolated from the marine sponge Cacospongia scalaris, were synthesized starting from polygodial via fungal hydroxylation and chemical modification, and the expected biological activities were obtained. All the structures of the products were determined by mainly spectroscopic means. A simple method for removal of chlorophyll was devised, resulting in considerable improvement in the yield of polygodial.