Efficient Preparation of Alkaloids Polycarpine and Polycarpaurines A and C

Abstract

An efficient method for the preparation of alkaloids polycarpine and polycarpaurines A and C via microwave‐assisted three‐step one‐pot reaction as the key step has been developed. This is the first report about the synthesis of polycarpaurines A and C. Starting from commercially available p‐methoxybenzaldehyde, polycarpine and polycarpaurine A were obtained over seven steps with 40 and 24 % overall yield, respectively. Polycarpine could convert to polycarpaurine C in 72% yield in the presence of NaHSO3. The structure of polycarpine and polycarpaurines A and C was confirmed by 1H NMR, 13C NMR, and HRMS.