Synthesis of the JK/LM-ring model of prymnesins, potent hemolytic and ichthyotoxic polycyclic ethers isolated from the red tide alga Prymnesium parvum: confirmation of the relative configuration of the K/L-ring juncture

Synthesis of the JK/LM-ring model of prymnesins, polycyclic ether toxins isolated from the red tide phytoflagellate, Prymnesium parvum, is described. Comparison of the 1H and 13C NMR data of the synthetic model with those reported for prymnesins confirmed the reported configurational assignment of the K/L-ring juncture.