Photosolvolysis of bridgehead quaternary ammonium salts. I. Synthesis of some 3-benzazonine derivatives

Abstract

The medium-ring heterocyclic derivative 7,9,10-trimethoxy-3-methyl-2,3,4,5,6,7-hexahydro-1H-3- benzazonine (10a) was obtained from the ultraviolet irradiation of the reduced pyrrolo[2,1-aliso-quinolinium iodide salt (9a) in methanol, along with N-[2-(3,4-dimethoxypheny1)ethyl]-4,4-dimethoxy- N-methylbutan-1-amine (11a) and N-[2-(3,4-dimethoxyphenyl)ethyl]-2-methoxy-N-methylpyrrol-idinium iodide (13a). Analogous products were also obtained from the photolysis of 8,9-dimethoxy- 4-methyl-1,2,3,5,6,10b-(10b-D)hexahydropyrrolo[2,1-a]isoquinolinium iodide (9b) and 8,9-di-methoxy-4,10b-dimethyl-1,2,3,5,6,10b-hexahydropyrroo[2,-a]isoquinolinium iodide (9c), with the exception of no pyrrolidinium salt from the latter. Photolysis of (9a) and (9c) in water afforded the corresponding hexahydro-1H-3-benzazonin-7-ols (10d) and (10e), and the amino aldehyde (12a) and the amino ketone (12b) respectively.