Contemporary synthesis of bioactive cyclobutane natural products

Many cyclobutane natural products have intriguing biological properties that arise from their fascinating chemical structures. Cyclobutane natural products feature a cyclobutane scaffold as the core or as a part of the spirocyclic or fused cyclic core. However, the highly functionalized nature and the inherent stereochemistry of these cyclobutane natural products, which are associated with their biological activities, pose tremendous challenges to their preparation. In this perspective, we present contemporary advancements in synthetic methods and/or strategies en route to the bioactive cyclobutane natural products. We begin by describing the representative bioactive cyclobutane natural products and then focus on illustrative examples of their syntheses reported from 2018 to 2021. These advances will enable efficient syntheses of cyclobutanes of structural and biological importance.