Peyote alkaloids IX: Identification and synthesis of 3-demethylmescaline, a plausible intermediate in the biosynthesis of the cactus alkaloids

The presence of 3-demethylmescaline in the alkaloidal mixture of peyote was proven by GLC-mass spectrometry through direct comparison. A new synthesis of this compound was realized by elaborating the ethylamine side chain onto the appropriately substituted benzene residue (with benzyl-etherification of the phenol group). The sequence involved transformation of the acid chloride successively into the diazoketone, the acid amide, and the ethylamine. A discussion is given of the possible role of 3-demethyl-mescaline and its congeners in the biosynthesis of peyote alkaloids.