Imerubrine and grandirubrine are the only known examples of the novel group of tropoloisoquinoline alkaloids. These are the minor alkaloids from several species of Abuta, which are topical vines belonging to the family Menispermaceae. The pharmacological properties of these unusual and rare bases are unknown and neither alkaloid has been synthesized as yet. The goal of this proposal is to synthesize imerubrine and grandirubrine as well as the parent troponoisoquinoline system by using several unrelated synthetic strategies.
