The recently discovered 1-phenethylisoquinoline class of alkaloids is represented by androcymbine and melanthioidine, while the biosynthesis of colchicine involves extensive modification of the 1-phenethylisoquinoline system. This work adds a further group by deriving homoaporphine structures (e.g., V) for three alkaloids from Kreysigia multiflora (Liliaceae): (-)-floramultine, (±)-kreysigine (previously isolated), and a new base named multifloramine. Structural analysis using mass spectrometry, NMR, IR, and UV spectroscopy indicated kreysigine as a tetracyclic alkaloid with a homoaporphine system. Synthesis confirmed the structures: the (-)-diphenol (I), prepared by standard methods, was oxidized to dienone (II), which rearranged to (±)-diphenol (III; multifloramine); methylation of (III) gave (±)-kreysigine (V) and its di-O-methyl ether (VI; O-methyl-(-)-kreysigine). Mass spectrometry corrected the molecular formula of (-)-floramultine to C21H23NO5; its methylation yielded (-)-kreysigine (V) and (-)-di-O-methylfloramultine (identical to (±)-O-methylkreysigine (VI)). Kreysigine (V), multifloramine (III), and floramultine (VII) are the first examples of homoaporphine alkaloids. Their occurrence in K. multiflora (related to Colchicum autumnale, containing colchicine and deacetylcolchicine) is of taxonomic interest. Biosynthetic pathways to these skeletons are being studied via tracer experiments on K. multiflora.