Spontaneous reaction of N,7,7-tricyanobenzoquinone methide imine (BMI) with 1-[(tri-methylsilyl.)oxy]-1-cyclohexene (1) was carried out at 60 degrees C in acetonitrile with the concentration of BMI below and above its equilibrium monomer concentration, and reaction products were analyzed. On the basis of the structure of the reaction products sind H-1 NMR spectra observed in situ for the reactions of BMI with 1 and of 7,7,8,8-tetracyanoquinodimethane (TCNQ) with 1, the initiation mechanism and a driving force to determine the addition direction for the-intermediate formation are discussed.