The Alkaloids of Lupinus varius L. III. The Structure of Base LV-1

Abstract

Base LV-1 (C₁₅H₂₂0N₂), isolated from the seeds and tops of Lupinus varius L., is converted by catalytic hydrogenation to (-)-sparteine. Partial reduction yields a ketonic base C₁₅H₂₄0N₂, shown to be 4-oxosparteine, and a study of the physical properties of base LV-1 leads to the alternative structures, Δ²- and Δ⁵-dehydro-4-oxosparteine. Decision between these alternatives is reached by examination of the nuclear magnetic resonance spectrum, which shows the presence of two vinyl hydrogen atoms, that is, base LV-1 is (-)-Δ²-dehydro-4-oxosparteine. Base LV-1 has been shown to be identical with multiflorine, isolated by Comin and Deulofeu (1959) from L. multiflorus Lam.