抄録
The takatonine-type compounds, (±)-1-(4-methoxybenzyl)-2-methyl-5-hydroxy-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline and its derivatives were synthesized via the Bischler-Napieralski ring-closure reaction. Correlation between the chemical Shift in NMR spectra and the conformation of these compounds and related compounds was examined. There are two stereochemical forms, called "s-cis" type and "s-trans" type conformation in the benzyl -benzene rings. It was concluded that the benzyl-benzene ring of tetrahydrotakatonine-type alkaloids takes the "s-cis" type conformation with respect to the benzene ring of isoquinoline moiety, while that of takatonine, papaverine, and N-methylpapaverine-type alkaloids take the "s-trans".
