Nemorensic acid (2)'is the diacid portion of retroisosenine (1) a molecule belonging to the family of natural products known as the Senecio alkaloids (Scheme I). These compounds have been of great interest owing to their diverse biological activity ranging from potent hepatotoxicity to antitumor acti~ ity.~,~ Only recently has progress been made in the total synthesis of some of the simple dilactone alkaloids in this class! Although the necine base ...
