A Synthetic Study towards the Marmycins and Analogues

A methodological study towards the total synthesis of marmycin A/B is described exploiting a commercial anthraquinone molecule as model compound. The challenging synthetic pathway uncovers a copper-catalysed Ullmann cross-coupling to attach the sugar backbone by means of C-N bond formation and, finally, an intramolecular Friedel-Crafts C-C glycosylation to successfully afford the core structure of marmycin A. This methodology has been successfully applied to the genuine anthraquinone moiety leading to the natural product and simpler structural analogues.