Studies on Tetrahydroisoquinolines. XXIV. A Synthesis of Dibenzo [c, f]-1-azabicyclo [3.3.1] nonanes and Dibenzo [d, g]-1-azabicyclo [4.3.1] decanes

Abstract

Treatment of the N-benzyl p-quinol acetates 2a and 2b with trifluoroacetic acid gave dibenzo [c, f]-1-azabicyclo [3.3.1] nonanes (3a and 3b) in good yields. The homologs 3c, 3d, and 3e were similarly prepared from the N-phenethyl p-quinol acetates 2c, 2d, and 2e, respectively. On the other hand, the o-quinol acetate (17), obtained from the tetrahydroisoquinolin-6-ol (9) by lead tetraacetate oxidation, was rearranged to the 4-acetoxy derivative (18). Acid treatment of 18 induced cyclization to construct the same skeleton as that of 3a.