The Alkaloids of Sedum spp

Two species of Sedum have been examined for alkaloids, i.e., Sedum acre L. and Sedum sarmentomm Bunge. The first yielded the alkaloids sedamine (83) and sedridine (84, 85), whereas the other contained IV-methyl isopelletierine and its dihydro derivative (86). 

This alkaloid is a crystalline solid, m.p. 89 , [a] —56.75° (ethanol) that was first assigned the empirical formula C17HJ4O2N (83), which was later corrected to C14H21ON (87). It forms a hydrochloride, m.p. 205°. The infrared absorption spectrum of the base and that of one of the forms of the diastereoisomer of l-methyl-2-(j8-hydroxy- 8-pheny-lethyl)-piperidine, prepared from phenyl-(a-pyridyl)-acetylene, were identical (88). 

Another synthesis was reported which consisted in the reduction of the condensation product of a-picoline methiodide with benzaldehyde (89). The substance obtained, however, has a considerably lower melting point than dZ-sedamine, and is probably a mixture of the two diastereo-isomerio forms. 

SchSpf (90) has reported that the condensation product of A -piperi-deine with benzoylacetic acid, after j Z-methylation and resolution, gives rise to sedamine identical with the naturally occurring base. 

Another path of synthesis consists in condensing J -methyl-a-piperidol with benzoylacetic acid at pH 5. A 50% yield is thus obtained of a-phenacyl-AZ-methylpiperidine which is dehydrosedamine (91). 

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