Construction of Spirocyclic Molecules from Cyclic β-Diketones.

In this review, recently developed straightforward and efficient strategies for the construction of spirocyclic molecules are summarized. Cyclic 1,3-diketones serve as versatile synthons and can be employed in one-pot, single-step reactions as well as in multistep sequences and multicomponent processes with a variety of reacting partners, including aldehydes, ketones, amines, isatins, and acenaphthoquinone. These transformations can be facilitated either by using stoichiometric amounts of reagents or under catalytic conditions, including nanoparticle-supported systems, often resulting in significantly enhanced yields of the desired spirocycles. Some of the spirocyclic frameworks display a wide range of biological activities, showing efficacy against cancer, microbial, and fungal targets, and thus represent promising candidates for future medicinal chemistry and drug development.