Synthesis of novel alkaloid derivatives from vinyl ether of lupinine and PH-addends

Abstract

A new family of functional quinolizidine alkaloids containing alkoxy groups and phosphine or phosphine chalcogenide fragments has been prepared from the vinyl ether of enantiomerically pure lupinine, secondary phosphines and phosphine sulfide. The reaction proceeds readily under radical initiation to give anti-Markovnikov adducts, dialkyl[2-(octahydro-2H-quinolizin-1ylmethyloxy)ethyl]phosphines and -phosphine sulfide, in high yields (89-96%). The phosphine moieties of the alkaloids synthesized have been oxidized with air, elemental sulfur or selenium to afford the corresponding phosphine chalcogenides.