4) The ligand effect was examined in detail in the reaction of 3,4-epoxy-2pentanone. Other multidentate phosphine ligands, such as bis(dipheny1phosphino)propane, (+~2,3-CXsopropylidene-2,3dihydroxy-l,4-bis(di-pheny1phosphino)butane (diop), or bis(2diphenylphosphinoethyl)phenylphosphine (a tridentate ligand), worked much less effectively. In the presence of such ligands, metal precipitation was avoided, but consumption of the starting material was slow. Unidentate ligands, P(CeH&, P(C&I&CH3, P(CH&C&, P(IFC~HQ)~, etc., did not give any satisfactory results either. The CY position of a,P-epoxy ketones is highly susceptible toward nucleophilic displacement. See Hwstmann, H. In "Methoden der organischen Chemie (Houben-Weyl)", Bayer, O., Ed.; Georg Thieme Verlag: Stuttgart, 1977; Vol. V11/2c, Chapter 9, p 2380. (8) Alternatively the hydrogen migration may occur via an 3-ketoenolate-palladium hydride complex formed by P-elimination in 3.(9) The accelerating effect by the added dpe ligand is notable, but the exact reason has not yet been elucidated. Fw related ligand effects on the reactivity of group 8 metal complexes, see: Yoshida, T.; Yamagata, T.; Tulip, T. H.; Ibers, J. A,; Otsuka, S.
