This review outlines recent progress in the total synthesis of cyclopropane-containing natural products, with a particular focus on the application of novel synthetic methodologies and tactics for assembling naturally occurring three-membered rings.

Covering: up to the end of 2023 Cephalotane diterpenoids are a unique class of natural products exclusive to the genus Cephalotaxus, featuring a rigid 7,6,5,6-fused tetracyclic architecture. The study of cephalotanes dates back to the 1970s, when harringtonolide (1), a Cephalotaxus troponoid with a peculiar norditerpenoid carbon skeleton, was first discovered. In recent years, prototype C₂₀ diterpenoids proposed as cephalotane were disclosed, which triggered intense studies on this diterpenoid family. To date, a cumulative total of 105 cephalotane diterpenoids with great structural diversity and biological importance have been isolated. In addition, significant advances have been made in the field of total synthesis and biosynthesis of cephalotanes in recent years. This review provides a complete overview of the chemical structures, bioactivities, biosynthetic aspects, and completed total synthesis of all the isolated cephalotane diterpenoids, which will help guide future research on this class of compounds.

Seventeen new cephalotane-type diterpenoids were isolated fromCephalotaxus fortuneivar.alpina. Compounds 14 and 15 contain an unusual 7-oxabicyclo[4.1.1]octane moiety.