Michael addition reaction in C-5 of Camptothecin

A simple method for Michael addition at C-5 of Camptothecin has been developed to construct 5-CPT derivatives. The addition products were obtained with moderate yields, and the structures of the target compounds were characterized by 1H NMR, 13C NMR, and HRMS spectra. The feasibility of various Michael addition acceptors for this reaction has also been investigated.