Complete assignment of the 13C NMR spectra of the ring forms of digitoxose by DEPT spectrum editing and two‐dimensional proton chemical shift correlation spectroscopy

Abstract

AbstractThe 13C chemical shifts of the four isomeric ring forms of D‐digitoxose in dimethyl sulfoxide‐d6 solution have been assigned completely by DEPT 13C NMR spectrum editing and two‐dimensional carbon–proton chemical shift correlation spectroscopy. The 13C chemical shifts are discussed in terms of their dependence on ring size and on anomeric configuration. The equilibrated mixture of four ring forms of D‐digitoxose in dimethyl sulfoxide‐d6 solution has been analysed quantitatively by 13C NMR spectroscopy, and the results compared with those obtained previously by 1H NMR.