With the analysis of the nuclear magnetic resonance spectra of protofarrerol (IA) and triacetylfarrerol (IIC), the chemical shifts and the coupling constants containing the relative sign are determined using the double resonance techniques, the spin-decoupling and the spin-tickling. Especially the ABX spin systems in these compounds give the similar conformation and the same relative sign of coupling constants, even if the substituent of C-2 position is a phenyl or a alicyclic ring. The computations for the spin systems are carried out with the simulations and the iterations.