3 NEW NAPHTHYLDIHYDROISOQUINOLINE ALKALOIDS FROM ANCISTROCLADUS-TECTORIUS

Three new 5-1'-linked naphthyldihydroisoquinoline alkaloids (1-3) have been isolated from the organic extract of Ancistrocladus tectorius. T he gross structures of the compounds have been established using 1D an d 2D NMR spectroscopy and difference NOE experiments. The absolute ste reochemistry of 1, 2, and 3 was determined from CD spectral comparison and chemical degradation, Evidence is presented to show that two of t he compounds exist exclusively in the keto form at C-8 of the isoquino line system (2b, 3b).