Transformation reactions of the betti base analog aminonaphthols

By means of simple or domino ring‐closure reactions of 1‐(α‐aminobenzyl)‐2‐naphthol (Betti base: 1), 1‐aminomethyl‐2‐naphthol (2) and 2‐(α‐aminobenzyl)‐1‐naphthol (reverse Betti base: 3) with phosgene, ethyl benzimidate, 2‐carboxybenzaldehyde, levulinic acid, salicylaldehyde/formalin or salicylaldehyde/acetaldehyde, naphth[1,2‐e][1,3]oxazine and naphth[2,1‐e][1,3]oxazine derivatives were prepared. All of the nitrogen‐bridged polycyclic derivatives of 1 and 3 containing a number of centers of asymmetry were formed with nearly complete diastereoselectivity. Considerable differences were observed in the ring‐closing abilities of the unsubstituted and phenyl‐substituted aminonaphthols 1 and 2 and of the regioisomeric compounds 1 and 3.