Palladium(O)-mediated Formation of γ-Methylene-γ-butyrolactone from allyl 4-pentenoate

Abstract
Synthetic organic reaction by means of transition metal carboxylate complexes continues to be a subject of active interest,1 in which the transition metal carboxylate complexes are generally generated by oxidative addition of allylic esters to low-valent transition metal complexes. It also relates closely to the utilization of carbon dioxide in organic synthesis by means of transition metal complexes, because carbon dioxide insertion into the transition metal-carbon bonds produces the transition metal carboxylate complexes.2 Very recently we have reported the formation of γ-butyroiactone by the reaction of bis (π-allyl)nickel (II) with carbon dioxide via a π-allynickel (II) 3-butenoate complex.3 Here we report Pd(PPh3)4- induced