The use of 1,4-dipolar aryne cycloaddition strategy in anthracyclinone synthesis: The formal synthesis of (±)-4-demethoxydaunomycinone

Article abstract of DOI:10.1055/s-1991-26373

We report herein the convergent synthesis of the 7,8,9,10-tetrahydro-9-hydroxy-6,11-dimethoxy-5,12-naphthacenedione (9), an advanced intermediate in the synthesis of (±)-4-demethoxy-daunomycinone, using the aryne dipolar cycloaddition reaction of lithiated 3-cyanophthalide and 2-bromo-5,6-dihydro-1,4-dimethoxynapththalene (6) in the key step. Similarly, the non-convergent synthesis of the 7,8-dihydro-4,6,11-trimethoxy-5,12-naphthacenedione (10), an important intermediate in the synthesis of (±)-daunomycinone, is presented.