Synthetic Studies on Anthracyclinones. IX. Lithiation of N, N-Dimethylnaphthalenemethylamines and a New Synthetic Pathway to 2, 3-Naphthalides

Abstract

Lithiation of ring-methoxylated N, N-dimethylnaphthalenemethylamines was investigated. The lithiation of 4-methoxy-2-naphthalenemethylamine types (XV and XVII) resulted in a setective lithiation on position 3, teading to an efficient method of β, β'-bis-carbon-substitution on the naphthalene or anthracene ring system. As an application, new syntheses of 1-oxygenated 2, 3-naphthalides (XXXII, XXXIII, XXXV, and XXXVI) or 5-oxygenated 2, 3-naphthatides (XLII) were accomptished via carboxylation of lithio derivatives, quarternarization of the resulting amino Qcids and subsequent pyrolysis.