A new technique for differentiating between 2J(C,H) and 3/4J(C,H) connectivities

We present a new pulse sequence that yields two simultaneously detected types of long-range correlation spectra. The one spectrum is to show all (n)J(C,H) connectivities and the other is to show exclusively (2)J(C,H) connectivities. The method is demonstrated by using strychnine as a test sample. A comparison with HMBC shows that the (2)J(C,H)/(n)J(C,H) experiment supplies a (n)J(C,H) spectrum that is of equal standard with regard to sensitivity and spectral information. The additional (2)J(C,H) spectrum allows the disentanglement of (2)J(C,H) and (n)J(C,H) signals (n > 2) in HMBC type spectra, which greatly simplifies signal assignment and structure elucidation in general. Copyright (C) 2003 John Wiley Sons, Ltd.