Enantiodivergent total syntheses of nanaomycins and their enantiomers, kalafungins

Article abstract of DOI:10.1246/bcsj.58.1699

The first, enantiospecific total syntheses of pyranonaphthoquinone antibiotics, nanaomycins D and A, and their enantiomers kalafungin and 4-deoxykalafunginic acid, are described by an 'enantiodivergent' strategy from a common optically active intermediate, (1S,3RS,4S)-3,4-dihydro-5,9,10-trimethoxy-1-methyl-1H-naphtho[2,3-c]pyr an-3,4-diol, which has been derived from L-rhamnose via condensation of 4-methoxy-3-(phenylsulfonyl)-1-(3H)-isobenzofuranone and methyl 3,4,6-trideoxy-α-L-glycero-hex-3-enopyranosid-2-ulose.