The semiempirical self-consistant field / modified neglect of differential overlap (SCF-MNDO) method has been used to calculate the energies of the highest occupied, lowest unoccupied and singly occupied molecular orbitals (HOMO, LUMO and SOMO) of some neutral furan-derivative molecules and their radical formed by addition of a dimeric vinyl acetate radical to the furan ring. Molecules with lower energy of the HOMO and LUMO behave as stronger retarders. This suggests an interaction with the attacking radical of the type SOMO-LUMO giving a more stabilized radical with lower SOMO energy. The rate of retarded radical polymerization of vinyl acetate in the presence of some furan compounds shows a good correlation with several sets of reactivity substituent constants and with the dipole moment obtained by quantum-mechanical calculations. However, the calculated enthalpies are low or positive and do not correlate. Besides, values of the reactivity substituent constants are suggested as 0.27 for the -CH2-NH2 side group and 0.74 for -CONH2.