SYNTHESIS OF ANSAMYCINS: AN APPROACH TO THE NAPHTHOQUINONE PORTION OF THE RIFAMYCINS AND STREPTOVARICINS
Naphthoquinone 1, a fully functionalized model for intermediates in ansamycin synthesis, was prepared by the intramolecular Claisen condensation of benzofuran 9 followed by oxidation of the novel tricyclic compound 10.