title: Hofmann elimination with diazomethane on curare bases and selected quaternary tetrahydroisoquinoline alkaloids.
abstract: Use of a large excess of alkali-free diazomethane resulted in a Hofmann elimination with selected curare bases and some other quaternary tetrahydroisoquinoline alkaloids. (+)-Tubocurarine chloride provided a monostilbene methine, O,O-dimethyltubocurinemethine, and a monostilbene--monostyrene compound, O,O-dimethyltubocurinedimethine. The major elimination products of (+)-isotubocurarine chloride and (+)-carnegine methiodide were monostyrene methines, O,O-dimethyltubocurineisomethine and carneginemethine, respectively. Treatment of (+)-laudanosine methiodide with potassium hydroxide, under the conditions of Hofmann degradation, or alkali-free diazomethane solution provided the same stilbene compound, laudanosinemethine. The structures of the elimination compounds were further confirmed by catalytic reduction and quaternization with methyl iodide.
mesh_terms: D000470:Alkaloids; D055598:Chemical Phenomena; D002621:Chemistry; D003978:Diazomethane; D007546:Isoquinolines; D000644:Quaternary Ammonium Compounds; D014403:Tubocurarine / Q000031:analogs & derivatives*
chemical_list: D000470:Alkaloids; D007546:Isoquinolines; D000644:Quaternary Ammonium Compounds; D003978:Diazomethane; D014403:Tubocurarine