A stereostructural study of 17-hydroxylupanine and its perchlorate

The bisquinolizidine carbinolamine 17-hydroxylupanine was synthesized de no vo from lupanine using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; its struc ture was established by NMR techniques. The equatorial position of the hydr oxy group as well as the prevailing boat form of ring C were determined. As expected, the carbinolamine converted into the C17=N16 anhydronium perchlo rate upon treatment with HClO4. NMR analysis of the salt revealed a conform ational equilibrium within rings A and D, whereas rings B and C remain rigi d.