REGIOSPECIFIC SYNTHESIS OF POLYSUBSTITUTED NAPHTHALENES VIA OXAZOLINE-MEDIATED NUCLEOPHILIC AROMATIC SUBSTITUTIONS AND ADDITIONS

An efficient procedure for the selective functionalization of several positions of 2-methoxynaphthalene is described. Nucleophilic aromatic substitutions were carried out by displacing both a methoxy group and a neutral amine ortho to an oxazoline 6. 4-Substituted naphthalenes 8 were obtained from nucleophilic aromatic addition of an allyllithium species to a position para to the oxazoline 6. The resultant dihydronaphthalenes were converted to the fully aromatic systems 9 or alternatively substituted in the 2-position to form 10. Reductive cleavage of the oxazoline moities in 7 and 9 proceeded smoothly, producing the substituted naphthaldehydes 11.