Abstract 2 Four3, 10, 11-tetraalkoxy-substituted 5, 6, 15, 15a-tetrahydro-8H-benzo [a] naphtho [1, 2-g]-quinolizines were prepared by the Pictet-Spengler cyclization of the respective 1-(6, 7-dialkoxy-2-naphthylmethyl)-6, 7-dialkoxy-1, 2, 3, 4-tetrahydroisoquinolines . The latter compounds were obtained by a chemical reduction of the corresponding dihydro compounds, which, in turn, were formed by a Bischler-Napieralski cyclization of the ...