Application of Photochemical Rearrangement of Santonin in Total Synthesis of Complex Natural Terpenoids

Terpenoids represent one of the largest and most diverse classes of secondary metabolites and widely exist in nature. Among them, sesquiterpene lactones are ubiquitous in a variety of medicinal plants, which are the main active ingredients of many traditional Chinese herbal medicines. However, it is extremely challenging to accomplish the total synthesis of these natural compounds. Photochemical rearrangement of santonin is an effective strategy to construct the guaianolide skeleton. Furthermore, as a renewable natural resource, santonin was extensively used in natural product total synthesis, especially complex terpenoids. In this review, a brief overview of application of photochemical rearrangement of santonin in total synthesis of natural terpenoids is presented, which mainly includes:(1) the synthesis of sesquiterpene and its oligomers, and (2) the core structure construction of some diterpenoids.