Gold(I)-catalyzed synthesis of γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with alcohols

• Michel Chiarucci,
• Mirko Locritani,
• Gianpiero Cera and
• Marco Bandini

Beilstein J. Org. Chem. 2011, 7, 1198–1204, doi:10.3762/bjoc.7.139

• outset of our investigation, we focused our attention on the non-enolizable allyl alcohol (Z)-1a, as a model candidate for the intramolecular oxaallyl alkylation. Our choice was dictated by the well-known reluctance of disubstituted malonyl derivatives to provide vinylbutyrolactones. This aspect was

• allylic SN1 mechanism is involved in the present methodology, due to the similar optical outcomes obtained in the presence of BA metal-free catalysts (entry 15, Table 1). Then, enolizable substrates carrying different malonyl residues (1b–e) were taken into account. In all cases the cyclization occurred

• intermediates) [53][54][55] in the nucleophilic attack was excluded; non-enolizable compounds being suitable candidates for the cyclization reaction. Conclusions In conclusion, we have documented an unprecedented example of gold-catalyzed lactonization with primary allylic alcohols. Cationic NHCAu carbene gold