4‐substituted‐1,2,3,4‐tetrahydro‐3,3‐dimethylisoquinolines. II.

A practical synthesis (Scheme I) is described for the preparation of a series of 4‐substituted‐3,3‐dimethyl‐1,2,3,4‐tetrahydroisoquinolines ( 3 ). Treatment of α‐(1‐amino‐1‐methylethyl)arylmethanols or α‐(1‐amino‐1‐methylethyl)heteroarylmethanols ( 5 ) with aromatic aldehydes gave imines 7 from which amino alcohols 8 were derived by reduction with potassium borohydride. Acid catalyzed cyclization of 8 yielded 3 . An acyl substituent was installed by Friedel‐Crafts acylation as a final step. The biological activities of 3a (1) are briefly described.