Synthetic studies towards daphniyunnine B: Construction of AC bicyclic skeleton with two vicinal all carbon quaternary stereocenters

The AC bicyclic skeleton of daphniyunnine B with the required 3. stereocenters (C4, C5 and C8) was accomplished in a concise route which featured two Claisen-type rearrangement reactions to construct the required vicinal all carbon quaternary stereocenters (C5 and C8) and an intramolecular iodocyclization reaction to assemble the cis-confused bicyclic lactam. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.