Gold (I)-catalyzed an efficient and mild synthesis of 3,8-Diarylidene-2,7-dioxaspiro[4.4]nonane-1,6-diones

3,8-dibenzyl-2,7-dioxaspiro[4.4]nonane-1,6-diones are a class of compounds widespread in natural and bioactive compounds. For instance, natural compounds isolated from Carpesium abrotanoides with a similar γ-dilactones scaffold, such as dicarabrol A, dicarabrone C, and dipulchellin A, demonstrated promising biological activities such as anti-inflammatory, antitumor, antiplasmodial, and bactericidal effects.\r\nFor their remarkable properties, these compounds have always drawn the attention of researchers, and their construction by means of alternative routes is still a challenging research area. Herein, we reported on the synthesis of spirolactones starting from substituted dialkynylmalonic acids. In particular, we demonstrated that functionalized symmetric or unsymmetric biarylacetylenic malonic acids may be efficiently cyclized under mild conditions in the presence of JohnPhosAu(MeCN)SbF6. The reaction's scope was evaluated via the preparation of different substituted dialkynylmalonic acids that in the reaction condition gave the corresponding γ-arylmethylene-spirobislactones in excellent yields (96–100%). The results of our investigation show that this process may represent an easy and efficient approach to highly valuable building blocks of natural products or biologically active compounds.