α-Alkylation of a norbornene-derived tricyclic ketone: are steric factors really in control?

Density functional theory (DFT) has been used to investigate the alpha-alkylation of a chiral tricyclic ketone. These calculations reveal that torsional strain and a strong conformational preference, rather than steric influences, are responsible for the high levels of observed stereoselectivity and suggest a way by which alternative stereoisomers could be accessed.