In the presence of iodotrimethylsilane (TMSI) and lithium iodide in tetrahydrofuran, the otherwise unreactive copper acetylides add to enones present as s-trans conformers to provide good yields of the silyl enol ethers of β-acetylido carbonyl compounds. Typically good substrates are 2-cyclopentenone, 2-cyclohexenone, α, β-unsaturated aldehydes, and β-alkoxy-α-enones. Copper acetylide reagents prepared from CuI and an alkynyllithium ...