Interunit, through-space 1H-19F and 13C-19F spin-spin couplings of 5-fluorinated arbekacins.

5-Deoxy-5-fluoroarbekacin (1) and 5-deoxy-5,5-difluoroarbekacin (2) showed interunit, through-space 1H-19F spin-spin couplings at the signals for H-1', 4", 5", 6"a and 6"b with F-5eq. These couplings were detected by a new NMR method, 1H-detected 2D 1H-19F chemical shift correlation spectroscopy. These two compounds also displayed interunit, through-space 13C-19F couplings at the resonances for C-1' and 5" with F-5eq. These couplings were corroborated by 1D 13C[1H]-[19F] triple-resonance techniques. Triple-resonance 13C-19F COSY experiments were also carried out. The interunit conformational information obtained with the through-space 1H-19F and 13C-19F couplings was further supported by heteronuclear 1H[19F] NOE experiments.