γ-Hydroxynitrile Alkylations: Electrophile-Dependent Stereoselectivity†

Quaternary centers are efficiently installed in chelation-controlled alkylations of acyclic hydroxynitriles. Intriguingly, the stereoselectivity is determined by the nature of the electrophile and the structure of the Grignard used for the deprotonation. The alkylation strategy addresses the long-standing difficulty of performing diastereoselective alkylations with conformationally mobile, acyclic nitriles.