Zuordnung des 13C‐NMR.‐Spektrums von Rifamycin‐S Aufgrund der selektiven Protonen‐Entkopplung

Abstract 13C‐NMR. spectra of rifamycin‐S and some of its derivatives have been measured. A unambigous assignment of the signals, due to the hydrogen bearing 13C atoms, was possible with heteronuclear double resonance experiments. On the other hand the resonances of the quarternary 13C atoms could be ascribed only tentatively. 13C‐NMR. spectroscopy gives a more complete picture of the rifamycins, especially about the naphthoquinone chromophore, than previously obtained by 1H‐NMR.