Catalytic Asymmetric Inverse‐Electron‐Demand Diels–Alder Reactions of 2‐Pyrones with Indenes: Total Syntheses of Cephanolides A and B
Yang Lü, Mengmeng Xu, Zhi‐Mao Zhang, Junliang Zhang, Quan Cai
Abstract
An inverse-electron-demand Diels-Alder (IEDDA) reaction could complement the conventional normal-electron-demand Diels-Alder reaction in the synthesis of six-membered carbocycles. However, catalytic asymmetric all-carbon-based IEDDA reactions are underdeveloped. Herein, we disclosed a copper-catalyzed asymmetric IEDDA reaction using electron-deficient 3-carboalkoxyl-2-pyrones and electronically unbiased indenes as reactants. This method enables the rapid and enantioselective construction of a wide range of hexahydrofluorenyl bridged-lactone scaffolds. Using this method, asymmetric total syntheses of cephanolides A and B were accomplished.
Topics & Concepts
CatalysisEnantioselective synthesisChemistryDiels–Alder reactionCombinatorial chemistryOrganic chemistryBiological Activity of Diterpenoids and BiflavonoidsTraditional and Medicinal Uses of AnnonaceaeSynthetic Organic Chemistry Methods