Synthesis of the oxindole alkaloid (-)-Horsfiline

Article abstract of DOI:10.1016/S0957-4166(00)86273-4

A synthesis of (-)-horsfiline ((-)-1), a metabolite isolated recently from Horsfieldia syperba, is described. The diastereoface selectivity of the crucial oxidative rearrangement of chiral tetrahydro-β-carboline precursors into the corresponding oxindoles was investigated in some detail and found to depend critically on the substitution pattern of the aliphatic amino group. These findings were exploited for the preparation of(-)-1, as well as of the unnatural optical antipode (+)-1, starting from 5-hydroxy-L-tryptophan as the single source from the chiral pool.