Synthetic and Transformational Aspects of Ketene Acetals and Applications in Heterocyclic Chemistry

Abstract Thioketene acetals, ketene aminals, and ketene N,S ‐acetals, particularly those bearing an electron‐withdrawing group at the α ‐position, serve as valuable synthons for the construction of heterocyclic compounds. These motifs occur in a wide range of natural and synthetic products, many of which display notable pharmacological and other biological activities. Owing to their unique electronic properties, they undergo diverse transformations, including heterocyclization, 1,4‐addition, dimerization, nucleophilic substitution, and annulation. Such reactions can be carried out under various conditions, ranging from one‐pot and multi‐component strategies to catalyzed, uncatalyzed, and light‐mediated processes. This review summarizes recent reactions involving the synthesis and applications of ketene acetals, with a particular focus on studies published between 2020–2024, and discusses their applications in modern organic synthesis.