A detailed NMR analysis of 3',4-O-dimethylcedrusin and 4-O-methylcedru
sin using two-dimensional COSY, HETCOR and long-range HETCOR technique
s showed that some C-13 NMR spectral assignments reponed previously fo
r related dihydrobenzofuran lignans such as dihydrodehydrodiconiferyl
alcohol and dihydrocarinatinol must be revised.