Steric approach control is common in conjugate addition reactions. Thus, in cyclic substrates, a trans relationship between substituents on the α- and β-carbons is common. The configuration at the α-position is less predictable, especially in cases when epimerization can occur. On the basis of steric approach control, the new α-substituent is predicted to be trans to the new β-substituent, and this is observed in a number of cases.