Anthracyclinones. 2. Isosaccharinic Acid as Chiral Template for the Synthesis of (+)-4-Demethoxy-9-deacetyl-9-(hydroxymethyl)daunomycinone and (-)-4-Deoxy-γ-rhodomycinone

Article abstract of DOI:10.1021/jo00382a015

Chiral aldehyde derivatives 12, 19, and 22 were prepared in few steps from α-D-isosaccharino-1,4 lactone (1a).These derivative precursors of ring A of the title anthracyclinones were condensed with leucoquinizarin (28), the component of the BCD rings.Aldolization reactions afforded alkylanthraquinones 29, 33, and 34, respectively.After suitable transformations of 29 and ring closure, the protected anthracyclinone 27 was obtained.Acetal cleavage of 27 led to the (+)-4-demethoxy-9-deacetyl-9-(hydroxymethyl)daunomycinone (5).Similarly suitable transformations of 33 or 34 followed by ring closure gave the (-)-4-deoxy-γ-rhodomycinone (30).