2019/01/02 by Guang Li, Cyril Piemontesi, Qian Wang +1 · 2 citations
Pharmacology, Toxicology and Pharmaceutics · Biochemistry, Genetics and Molecular Biology · Chemistry · #Alkaloids: synthesis and pharmacology #Traditional and Medicinal Uses of Annonaceae #Chemical synthesis and alkaloids
paper · doi:10.1002/anie.201813920
openalex publication_date 2019/01/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Controlling the cis C20/C21 relative stereochemistry remains an unsolved issue in the synthesis of eburnane-type indole alkaloids. Provided herein is a simple solution to this problem by developing a unified and diastereoselective synthesis of four representative members of this class of natural products, namely, eburnamonine, larutensine, terengganensine B, and melokhanine E. The synthesis features the following key steps: a) an α-iminol rearrangement transforming the 3-hydroxyindolenine into spiroindolin-3-one, b) a highly diastereoselective conformation-directed cyclization leading to the melokhanine skeleton with the desired C20/C21 cis stereochemistry, and c) either an aza-pinacol or an unprecedented α-aminoketone rearrangement converting spiroindolinone back into the indole skeleton.