A practical and concise total synthesis of tricyclic ketone 7 (CDE ring), a valuable intermediate for the
synthesis of racemic camptothecin and analogs, was described (8 chemical steps and 29% overall yield). The
synthesis starts with two inexpensive, readily available materials and is operationally simple to perform. It is
worth mentioning that the reported protecting group-free synthesis, with advantages of a short route, would be
helpful for the future development of industry-scale syntheses of camptothecin-family alkaloids.