Fused carbocycles are key structural elements of molecules in nature and they are often found in drugs and organic materials, but bicyclic systems containing six and seven-membered rings are difficult to prepare. Here, the authors functionalize an azulene skeleton that consists of fused five and seven-membered rings and carry out a ring expansion reaction to afford the desired bicycles.
- Sangjune Park
- Cheol-Eui Kim
- Phil Ho Lee