Reaction of Lithiated Senecioamide and Related Compounds with Benzynes : Efficient Syntheses of Naphthols and Naphthoquinones

Abstract

The reaction of lithated N, N-diethylsenecioamide and N, N-diethy-3-phenlisocrotonamide with methoxy-substituted benzynes, generated in situ from methoxy-substituted halobenzenes, gave regiospecifically various 3-methyl- and 3-phenyl-naphthol derivatives in a one-pot process. Methoxy-substituted 3-methyl-1-naphthols thus obtained were easily converted into various 1, 4-naphthoquinones and 1, 2-naphthoquinones including biologically active natural products such as plumbagin, plumbagin methylether, 5, 6-dimethoxy-2-methyl-1, 4-naphthoquinone, and 8-methoxy-3-mathyl-1, 2-naphthoquinone.