INTERUNIT, THROUGH-SPACE H-1-F-19 AND C-13-F-19 SPIN-SPIN COUPLINGS OF 5-FLUORINATED ARBEKACINS

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