A novel and efficient synthesis of xanthones is described. 2-(Trimethylsilyl)phenyl 2-fluorobenzoate derivatives undergo Fries-type rearrangement and intramolecular SNAr reaction in a one-pot sequential manner under fluoride ion-promoted mild conditions. The method provides efficient access to xanthones that have significant steric congestion around the C9 carbonyl, which are not readily available
and 17, useful intermediates toward the angucyclines, either benz[a]anthraquinone-type or naphthacenequinone-type, has been developed based on (1) the O→C-glycoside rearrangement and (2) the regioselective cycloaddition of α-alkoxybenzyne and α-oxyfuran. The first totalsynthesis of galtamycinone (2), the common aglycon of naphthacenequinone-type angucyclines, has been achieved by utilizing 17 as the
An efficient two-step access to C-glycosyl juglones, promising synthetic intermediates toward aryl C-glycoside antibiotics, has been developed based on (1) the O → C-glycoside rearrangement and (2) the regioselective cycloaddition of α-alkoxybenzyne and α-oxyfuran.