Syntheses of Naphthalenes Utilizing Intramolecular Cyclization of 2-(Substituted benzyl)-1-propenylidene Compounds

Abstract

Reactions of 2-cyano-4-(m-methoxypheny1)-3-methy1-2-butenenitrile (2) and ethyl 2cyano-4-(m-methoxypheny1)-3-methyl-2-butenoate (3) with concentrated sulfuric acid afforded 2, 3, 6-trisubstituted 1-naphthylamines ( 4 ) and (5 ), respectively. Reaction of (3)with acetamide afforded 2, 3, 8- and 2, 3, 6-trisubstituted 1-naphthols, (6 ) and ( 7). Compounds, (8 ) and ( 9 ) obtained by methylation of (6 ) and (7), reacted with methylmagnesium iodide to give 2-acetyl-1-naphthols, (1O) and (1 1), which were analogous to musizin (2acetyl-3-methy1-1, 8-naphthalenediol).