A Synthesis of α,β-Unsaturated Ketones from α,β-Unsaturated Nitriles

An effective sequence for the synthesis of α,β-unsaturated ketones involves (1) the Horner-Emmons modification of the Wittig reaction to synthesize α,β-unsaturated nitriles, R₂CH₂(R₁)C=C(R₃)CN, from carbonyl compounds, R₂CH₂COR₁, and (2) the oxidative decyanation of the α,β-unsaturated nitriles to afford.ß-unsaturated ketones, R₂CH=C(R₁)COR₃, by sequential treatment with lithium diisopropylamide, oxygen gas, sodium sulfite, and sodium hydroxide.