Synthesis and stereochemical confirmation of the HI/JK ring system of prymnesins, potent hemolytic and ichthyotoxic glycoside toxins isolated from the red tide alga

Stereocontrolled synthesis of the HI/JK ring model of the prymnesins, glyosidic toxins isolated from the red tide phytoflagellate Prymnesium parvum, is described. Comparison of its 1H and 13C NMR data with those of the natural toxins established the earlier stereochemical assignments.