Convenient preparative method of α,β-disubstituted cyclopentenone by zirconium promoted intermolecular coupling of an alkyne, EtMgBr (or ethylene) and CO

Article abstract of DOI:10.1016/S0040-4020(97)00612-1

Treatment of Cp2ZrCl₂ with 2 equiv of EtMgBr in THF, followed by addition of an internal alkyne and subsequent treatment with CO/I₂ gave α,β-disubstituted cyclopentenone in good to high yields. When a conjugated enyne was used as an