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

摘要

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.