Recent advances in the total synthesis of cyclobutane-containing natural products

Complex natural products bearing strained cyclobutane subunits, including terpenoids, alkaloids and steroids, not only display fascinating architectures, but also show potent biological activities. Due to their unique structures as critical core skeletons in these molecules, a variety of new strategies for the construction of cyclobutane rings have greatly emerged during the last decade. In this review, we wish to summarize the recent progress in the cyclobutane-containing natural product synthesis with an emphasis on disconnection tactics employed to forge the four-membered rings, aiming to provide a complement to existing reviews.