Total synthesis of (+/-)-lennoxamine and (+/-)-aphanorphine by intramolecular electrophilic aromatic substitution reactions of 2-amidoacroleins

[GRAPHICS] Intramolecular electrophilic aromatic substitution reactions of 2-amidoacro leins constitute the key steps in the total syntheses of lennoxamine and ap hanorphine. The aldehyde moiety of one cyclization product was transformed to a double bond, which was then engaged in a radical cyclization to produc e the complete ring system of lennoxamine. The aldehyde functionality of th e other cyclization product was converted to the corresponding mesylate, wh ich underwent intramolecular displacement by a lactam enolate to furnish th e ring system of aphanorphine.