2023 Volume 81 Issue 2 Pages 115-126
Oxygen-containing ring structure is one of the characteristic substructures found in many natural organic compounds. Among them, a lot of natural products with ether ring structures have been reported to exhibit noteworthy and potentially useful biological activities, attracting much attention from natural product chemists and medicinal chemists. In addition, oxacyclic natural products listed as lead candidate compounds for pharmaceuticals often have unique chemical structures, which have been the attractive targets for extensive studies on their total synthesis by synthetic organic chemists. Although, needless to say, the shortness of the total reaction steps is the primary target of pursuit, in general, steric control of chiral centers as well as geometry is also an important issue for the efficient synthesis of complex natural products. The authors, in this research, have taken up amphirionin-4, anthecularin, and celafolin B1, B2, and B3, ether ring-containing natural products that exhibit remarkable biological activities, as synthetic targets, and have conducted synthetic studies toward their total syntheses with a particular focus on stereoselective construction of chiral centers. As a result, the authors found out stereospecific reactions based on the three-dimensional characteristics of certain synthetic intermediates, which abled construction of efficient and scalable synthetic routes. In this paper, the details of our synthetic studies on the asymmetric total syntheses of amphirionin-4, anthecularin, isocelorbicol, and celafolin B1, B2, and B3 are described.
