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Updated: May 20, 2026

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
Protecting group-free total synthesis of (-)-lannotinidine B
Hui Ming Ge1, Lan-De Zhang, Ren Xiang Tan
1State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, Institute of Chemical Biology and Drug Innovation, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China.
Abstract:
The first total synthesis of (-)-lannotinidine B, a unique tetracyclic constitutent of Lycopodium annotinum, has been accomplished in 10 steps with 23% overall yield. The completed short and efficient synthesis is characterized with three highly chemo- and/or stereoselective reductive-amination steps to furnish the desired trans-fused 6/6 bicycle and the aza seven-membered ring system, and a direct intramolecular acyloin condensation to deliver the cyclopentanone moiety, as well as successful application of a protecting group-free strategy and an optimal redox order.
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