Progress toward the total synthesis of the α-adrenergic blocking agent dispegatrine as well as the first enantiospecific total synthesis of lochvinerine, (+)-16-episarpagine, and lochnerine

ORGN 748

Chitra R. Edwankar,, Rahul V. Edwankar,, and James M. Cook, Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 N. Cramer St., Milwaukee, Milwaukee, WI 53211
Spegatrine and its dimer diespegatrine (1) belong to the sarpagine class of indole alkaloids.They have been reported to exhibit α-adrenergic blocking activity. The affinity of dispegatrine at α1 and α2-adrenoreceptors is about an order of magnitude larger than that of spegatrine. The enantiospecific total synthesis of monomers lochvinerine, (+)-16-Episarpagine and lochnerine as well as progress toward the total synthesis of the dimer (1) will be presented.