SYNTHETIC STUDIES ON NOGALAMYCIN CONGENERS ; CHIRAL SYNTHESIS OF THE CDEF-RING SYSTEM OF NOGALAMYCIN

Article abstract of DOI:10.1016/S0040-4020(01)81432-0

The chiral synthesis of the (+)-naphthoquinone (4), the CDEF-ring system of nogalamycin congeners, has been accomplished following the synthetic scheme developed for the model (-)-DEF-ring system (3) in the preceding paper.This synthesis features (1) stereoselective construction of the C_5'-asymmetric center by introducing the naphthalene moiety into the (-)-methyl ketone (5), the glycoside part, (2) regioselective oxidation of the 1,4,5,8-tetramethoxynaphthalene moiety with cerium(III) ammonium nitrate, and (3) efficient formation of bicyclic acetal system.