THE SYNTHESIS OF DEHYDROLUPANINES AND THE STEREOCHEMISTRY OF THE C15 LUPIN ALKALOIDS

Abstract

Two new dehydrolupanines, C15H22N2O, have been prepared: (1) by the mercuric acetate dehydrogenation of the alkaloid d-lupanine, and (2) by the N-bromosuccinimide dehydrogenation of d-lupanine. The conversion of d-lupanine to its diastereoisonieric alkaloid d-α-isolupanine has been effected by mercuric acetate dehydrogenation followed by catalytic hydrogenation. On the basis of evidence and knowledge at present accumulated it has been possible to assign absolute stereochemical structures to a number of C15 lupin alkaloids.