¹H and ¹³C NMR spectral assignments of some natural abietane diterpenoids

An NMR study of 11 naturally occurring abietane diterpenoids is described. In addition to one‐dimensional NMR methods, including DPFGSE 1D‐NOE spectra, two‐dimensional shift‐correlated experiments [ 1 H, 1 H COSY, 1 H, 13 C‐gHSQC 1 J (C,H) and 1 H, 13 C‐gHMBC n J (C,H) ( n = 2 and 3)] were used for the complete and unambiguous 1 H and 13 C chemical shift assignments of these substances.