The mode of incorporation of 2H from [3,3-2H2]cadaverine into lupanine (2) and 13α-hydroxylupanine (3) in Lupinusangustifolius was determined by 2H nmr spectroscopy. Lupanine carried deuterium at positions 4α, 4β, 8α, 8β, 13α, and 13β. These six sites were approximately equally enriched. Similarly, 13α-hydroxylupanine carried label approximately equally at five sites, 4α, 4β, 8α, 8β, and 13β. [3,3-2H2]Cadaverine was prepared by borodeuteride reduction in D2O of the p-toluene-sulfonylhydrazone of N-benzoylpiperid-4-one, followed by degradation of the resulting N-benzoyl[4,4-2H2]piperidine into 1,5-dibromo[3,3-2H2]pentane, conversion into 1,5-diphthalimido[3,3-2H2]pentane, and acid hydrolysis.