Synthetic Strategy for Construction of Highly Congested Tetracyclic Core (6–5–7–4) of Harziane Diterpenoids
Qian Tu, Zheyuan Wang, Zhongchao Zhang, Jun Huang, Zhen Yang
Abstract
The structurally intriguing tetracyclic core of complex harziane diterpenoid was constructed in 14 steps from commercially available 3-ethoxycyclohex-2-en-1-one. The key steps were a Mn/Cu-mediated oxidative 1,3-dicarbonyl radical cascade cyclization reaction, which diastereoselectively formed the core of dimethylbicyclo[3.2.1]octane structure, and a Au-catalyzed diastereoselective formal [2 + 2] cycloaddition for construction of the harziane diterpenoid tetracyclic framework. The developed method paves the way for achieving total synthesis of this type of complex natural product.
Topics & Concepts
ChemistryOctaneCore (optical fiber)Natural productStereochemistryCycloadditionTerpenoidCombinatorial chemistryFormal synthesisCascadeRadical cyclizationRing (chemistry)CatalysisOrganic chemistryComputer scienceTelecommunicationsChromatographyAdvanced Synthetic Organic ChemistryBioactive Natural Diterpenoids ResearchChemical synthesis and alkaloids